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                                                                   EXHIBIT 10.15

                                    SeaMED
                                    ------
                               A PLEXUS.Company
                        Professional Services Agreement
       (For Use with Manufacturing Services for Medical Customers Only)

This Agreement is hereby entered into on this 17th day of February, 2000 by and
between Rita Medical Systems, Inc., of 967 N. Shoreline Boulevard, Mountain
View, CA 94043, (hereinafter "Customer") and Plexus Corp. of 55 Jewelers Park
Drive, Neenah, WI 54956, (along with its wholly-owned subsidiaries Plexus
Technology Group, Plexus Electronic Assembly and SeaMED, a Plexus Company,
hereafter collectively referred to as "Plexus".)

A.   MANUFACTURING PHASE
------------------------

The terms and conditions set forth in this Section A, Manufacturing Phase,
Section B, Medical Device Provisions, as well as the terms and conditions set
forth in Section C, Standard Terms and Conditions, shall be applicable to this
portion of the Agreement. The parties may conduct a mutual review of component
pricing, material mark-up, and labor on a semi-annual basis. Unit prices shall
not be increased or decreased more often than semi-annually unless the quantity
on order changes, or in the event of an engineering change that impacts either
material or labor costs. [***] Attachment C provides an example of unit cost
calculations for various production rates. As part of the semi-annual reviews,
Plexus shall review unit costs at various production rates and shall provide
Customer with updated unit costs at these production rates. Customer's Purchase
Orders for quantities outside the scope of Attachment C shall be mutually
negotiated. The estimated quantity of Products is a factor used to determine
unit pricing. In the event of a significant quantity change, either increasing
or decreasing the estimated quantity of assemblies, the parties agree to
evaluate and negotiate the impact and timing of unit price adjustments.

1.   DEFINITIONS
----------------

For the purpose of this Manufacturing Phase:

"Assemblies" shall mean finished Product.

"Long Lead Time Component(s)" shall mean all of those individual parts and
materials whose current lead times extend beyond forty (40) business days. The
Long Lead Time Components may, from time to time, be reviewed by Plexus and
Customer, at the request of either party due to possible changes in market
conditions of supply and demand affecting the procurement by Plexus of the
Components and/or Long Lead Time Components for the assemblies hereunder. Any
changes resulting from such review shall be with the mutual written agreement of
Plexus and Customer.

"NCNR Component(s)" shall mean those parts that are not cancelable once placed
on order with Plexus suppliers, and are not returnable once delivered to Plexus.
The NCNR Component(s) may, from time to time, be reviewed by Plexus and
Customer, at the request of either party due to possible changes in market
conditions of supply and demand affecting the procurement by Plexus of the
Components and/or NCNR Component(s) for the assemblies hereunder. Any

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
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changes resulting from such review shall be with the mutual written agreement of
Plexus and Customer.

"Special Component(s)" shall mean those parts that have special procurement
conditions such as limited change parameters or other special liability
conditions that are required by Plexus' suppliers. The Special Component(s) may,
from time to time, be reviewed by Plexus and Customer, at the request of either
party due to possible changes in market conditions of supply and demand
affecting the procurement by Plexus of the Components and/or Special
Component(s) for the assemblies hereunder. Any changes resulting from such
review shall be with the mutual written agreement of Plexus and Customer.

"Monthly Rolling Quantity Forecast of Delivery Requirements" shall mean the
written documents provided to Plexus by Customer each month indicating the
delivery requirements projected for the next twelve (12) months.

2.   AUTHORIZATION OF WORK/PROCUREMENT OF MATERIALS
---------------------------------------------------

The following terms will apply assuming Customer's credit has been established
to Plexus' satisfaction:

a)   The purpose of this section is to define the methods under which Plexus
will procure materials to support manufacturing of product for the Customer. The
intent is to provide the Customer with flexibility to alter and/or cancel
schedules within a reasonable period of time while at the same time minimizing
Plexus liability that is a result of those alterations and cancellations. In
order to offer the best possible price, Plexus does not attempt to build
unanticipated carrying charges into its price. When changes in Customer
requirements occur that cause Plexus to incur unanticipated expenses that are
the result of Customer actions, the Customer is expected to reimburse Plexus for
the costs incurred.

For each assembly to be manufactured, Plexus establishes a manufacturing lead
time, which is the number of business days it will take, on average, to receive
and kit all components, assemble, test and ship the lot. Manufacturing lead time
shall be established during the pre-production phase of the program. Plexus
schedules all components for a particular lot of assemblies to arrive one
manufacturing lead-time prior to the Customer due date. Plexus then uses this
information, together with the Forecast and Purchase Order information as
defined below, to place commitments to its suppliers for materials.

b)   Customer shall place purchase orders for the first six (6) months of
production and maintain six (6) months of firm purchase orders on a month to
month rolling basis. Customer will provide Plexus on a monthly basis with a
minimum of twelve (12) month schedule of demand for product. The schedule will
show firm orders for months 1-6 and forecasted demand for months 7/12. Customer
authorizes Plexus to procure, as material lead times dictate, the material to
support 100% of Buyers forecasted requirements for months 7 through 9. On a
quarterly basis Plexus will place orders for material for months 7 through 9 of
the current forecast in order to lot size Printed Circuit Board Assemblies and
to determine economic order quantity buys or components or unique parts. Months
10, 11 and 12 are provided for Plexus

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
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visibility and may be utilized by Plexus to request additional material
authorizations from Customer. Prior to entering full production Customer and
Plexus will review the final bill of material, discuss material lead times and
production ordering parameters. Customer and Plexus agree to develop a material
ordering plan which will ensure timely delivery of material to meet production
objectives, while limiting the exposure to materials in the event of a program
shut down.

c)   Schedule Changes:

The Customer may request a change to the delivery schedule at any time. Schedule
changes can have an extraordinary effect on the amount of inventory at Plexus,
the impact for which is not considered in the original cost of the assembly.
Frequent schedule changes may result in additional administrative charges
including but not limited to administrative charges required for Plexus to
reschedule component deliveries.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Customer and Plexus recognize that each program is unique and will require
program specific ordering parameters. These parameters are mutually agreed to
after the bill of material is finalized and production quantities are provided
to Plexus in the form of a purchase order or delivery forecast. The parameters
set forth below offer a typical scenario where the Customer may, without cost or
liability, but with the assent of Plexus, reschedule deliveries of Products
already on order. Customer may request to move in delivery dates of quantities
on order. Plexus will complete an analysis of material availability and will
provide Customer with estimated ship dates based on material availability.
Likewise, Customer may request to move out delivery dates of quantities on
order. Plexus will complete an analysis of the impact of this change to material
on hand and on order. If Customer chooses to move out deliveries and material is
already at or shipping to Plexus's facility, Customer may be charged an
inventory deposit for this material as set forth below.

                    Production Schedule Ordering Parameters
                    ---------------------------------------

--------------------------------------------------------------------------------
0 to 3 Months       Firm PO's, Schedule unchangeable
--------------------------------------------------------------------------------
4 to 6 Months       Firm P0's. May move up to 20% of scheduled deliveries on
                    PO's out 30 days without incurring an inventory deposit, or
                    in 30 days depending on material availability.
--------------------------------------------------------------------------------
7 to 9 Months       May move up to 30% of scheduled deliveries on PO's out 60
                    days without incurring an inventory deposit, or in 60 days
                    depending on material availability. Deliveries extended >60
                    days will require an inventory deposit.
--------------------------------------------------------------------------------

Customer may request to increase the total quantity of Products on order. For
quantity increases, Plexus will make its best effort to obtain the components
necessary to meet Customer requirements. Plexus will complete an analysis of
material availability and will provide Customer with estimated ship dates based
on material availability. However, Plexus may be unsuccessful in obtaining all
of the components required to meet the Customer's increased requirements. In
that situation, Plexus will complete an analysis of material availability and
will provide Customer with estimated ship dates based on material availability.
Customer may request to decrease the total quantity of Products on order. If
Customer decreases the total quantity of Products on order, all non-cancelable,
non-returnable material procured in accordance with Customer's original Purchase
Order schedule will be the responsibility of Customer.

d)   Engineering Change

The term "Engineering Change(s)" (hereinafter called "EC" or "EC's") shall mean
those mechanical, software, or electrical design and/or specification and
requirement changes which, if made to the assemblies to be delivered hereunder,
would affect the schedule performance, reliability, availability,
serviceability, appearance, dimensions, tolerance, safety or purchase price of
such assemblies or which would require additional approval test.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Plexus may determine that Engineering Changes will affect its ability to
maintain the delivery schedule, due to the lead time of newly specified parts
and/or the impact of substantial rework or modification. Under these
circumstances, Plexus reserves the right to define a new schedule for delivery
and treat this as a Schedule Change, with the Customer liability as defined
under the Schedule Change condition.

Plexus shall process engineering changes per the agreed upon Document Change
Control Agreement, attached hereto and made a part hereof as Attachment A. Upon
receipt, Plexus shall review Customer's proposed EC and Plexus shall give to
Customer a written evaluation of the EC, stating Plexus' cost to implement the
EC (including the cost to modify any tooling), the excess quantity of Components
and/or Long Lead Time Components, NCNR Components and/or Special Components
Plexus has inventoried and/or has on order with its Components and/or Long Lead
Time Components, NCNR Components and/or Special Components suppliers that are
unusable for any other assembly requirement and excess due to the EC, and
associated costs and expenses such Components and/or Long Lead Time Components,
NCNR Components and/or Special Components that Customer shall be liable for and
the cost savings, if any, resulting from the EC, and the expected effect on the
schedule, availability and/or purchase price of such assemblies, or which may
require additional approval tests by Customer.

e)   Customer Supplied Parts

In the event the Customer supplies material to Plexus for use in the
manufacturing of the product, Customer agrees to supply the material on time and
in accordance with purchase orders placed by Plexus. Customer supplied material
will be subject to normal incoming inspection, and the value of the incoming
material will be included in the unit price. For purposes of payment relating to
this section only, Plexus and Customer agree to develop a method for providing
Customer with payment for such accepted customer supplied material such that
Customer will not be charged twice for any individual customer supplied
material. If material supplied by Customer is rejected or not delivered on time,
therefore preventing Plexus from completing and shipping product, Plexus may
invoice Customer for the full unit price as listed on Customer's purchase order.

f)   Minimum Component Purchases

Plexus may have to place orders for quantities of components in excess of that
required to support Customer requirements. This may be as a result of minimum
order size requirements or standard package sizes from the supplier. Plexus and
Customer will work together using best efforts to identify components that
require or may be likely to require a minimum buy prior to the initial build.
However, the Customer's responsibility for minimum component purchases is not
solely confined to this list since additional components may require minimum buy
purchases at any time. Plexus shall provide Customer with periodic updates as
well as inventory reports showing excess and obsolete components. The Customer
will agree to have the cost of the excess components amortized over a maximum of
six (6) month's requirements, or will place a purchase order separately for the
excess components.

g)   Cancellation

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Customer may cancel requirements defined in orders and/or forecasts at any time
before the scheduled delivery date. Any assembly requirements canceled within
the manufacturing lead-time of the scheduled delivery date will be invoiced at
the full agreed to price for the completed assembly.

For assembly requirements canceled outside the manufacturing lead time of the
scheduled delivery date, Customer's liability to Plexus will be the value of the
components in Plexus' inventory (including the full markup as defined in the
Plexus quotation), and other components for which Plexus has liability but which
are not in Plexus inventory, as well as payment for any and all work-in-process
(WIP) manufacturing costs and expenses, and reasonable administrative costs and
expenses. Plexus will deliver an itemized list of these costs to customer.
Customer agrees to pay the costs identified by Plexus within ten (10) business
days of notification of such costs.

To help minimize the impact of cancellation charges, Plexus will attempt to
restock components at the supplier, resell the components, and/or utilize the
components on non-customer assemblies.

3.   PAYMENT
------------

As full compensation for the assemblies and spare parts (i.e. to include but not
limited to components shipped to Customer for field service) provided by Plexus
hereunder and its obligations contained herein. Customer will make payments
subject to terms of net amount due thirty (30) days following the date of the
invoice. Unless stated otherwise, prices quoted are F.O.B. Plexus' manufacturing
facility. Unless specifically stated otherwise, all quoted prices are firm for
thirty (30) days from the date of quotation. Quotations are based on drawings,
specifications, and other written information available to Plexus at the time of
quotation. Any additional data supplied at the time of purchase may necessitate
price adjustments. Any manufacturer's tax, retailer's occupation tax, use tax,
sales tax, excise tax, or tax of any nature whatsoever imposed on or measured by
the transaction between Plexus and Customer shall be paid by the Customer in
addition to the prices quoted or invoiced. In the event Plexus is required to
pay such tax, the Customer shall reimburse Plexus therefore, within ten (10)
days of written demand by Plexus to the Customer for such reimbursement. If the
transaction between Plexus and the Customer is exempt from all such taxes,
Customer shall provide Plexus with a tax exemption certification or other
document acceptable to all taxing authorities at the time the order or contract
is submitted.

4.   WARRANTY
-------------

PLEXUS EXPRESSLY WARRANTS THE WORK AS SET FORTH HEREIN. PLEXUS MAKES NO OTHER
WARRANTIES, EITHER EXPRESS OR IMPLIED (INCLUDING WITHOUT LIMITATION WARRANTIES
AS TO MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSES). IN ADDITION, THE
FOLLOWING SHALL CONSTITUTE THE EXCLUSIVE REMEDIES FOR CUSTOMER FOR ANY BREACH BY
PLEXUS OF ITS WARRANTIES HEREUNDER.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Plexus warrants the assemblies against all defects in workmanship where the
assemblies do not conform to the agreed upon manufacturing specifications, for a
period of twelve (12) months from date of delivery to Customer's end-user, not
to exceed 16 months from date of invoice from Plexus, provided agreed upon
testing is conducted by Plexus prior to shipment, except as set forth below.
Plexus shall repair or replace, at Plexus' option and free of charge, any
portion of the assemblies which is returned to Plexus' factory securely
packaged, insured and with freight pre-paid within the warranty period, and
which upon examination Plexus determines in its sole discretion to be defective
in workmanship. Plexus will return the repaired or replaced assemblies to
customer with freight pre-paid. Plexus will pay for inbound freight for any new
units delivered dead on arrival (DOA) to Customer. DOA is defined as any product
that does not perform in compliance with the applicable mutually agreed upon
specifications upon receipt by Customer. Plexus agrees to pay return freight to
Customer and method of shipment will be consistent with the method of inbound
freight to Plexus.

This Warranty does not apply to:

a)   Design deficiencies.  Plexus expressly disclaims any warranty
responsibility for design deficiency, and for infringement for the like.

b)   Any modifications and/or alterations made to the Assemblies, or any portion
thereof, without the express written authorization of Plexus obtained in
advance. If this is the case, all warranties made herein are invalid and
Customer shall have no further remedies hereunder against Plexus.

c)   Any defect, loss or damage resulting from theft, loss, fire, misuse, abuse,
negligence, vandalism, acts of God, accident, casualty, power failures or
surges, alteration, modification or failure to follow installation, operation or
maintenance instructions, or any other cause beyond Plexus' reasonable control.

d)   Any defect, unless written notice of the defect is given by the Customer to
Plexus as soon as practical after the defect first appears. The right to make a
claim under this warranty expires twelve (12) months from the date of delivery
to Customer's end-user, not to exceed 16 months from date of invoice from
Plexus.

e)   Components incorporated into the assemblies.

In the event of any recall of any Product, caused by Plexus's sole negligence,
and within product warranty as defined, (i) Plexus shall repair or replace, at
Plexus' sole discretion, the recalled Product without charge to Customer, and
(ii) Plexus shall reimburse Customer for its reasonable out-of-pocket expenses
incurred in connection with such recall up to a maximum of $100,000.

IN NO EVENT, REGARDLESS OF CAUSE, SHALL EITHER PARTY BE LIABLE FOR INCIDENTAL,
INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSSES OF ANY KIND, WHETHER IN
CONTRACT OR IN TORT, ARISING FROM ITS PERFORMANCE UNDER THIS SECTION.

5.   TEST EQUIPMENT
-------------------

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Unless otherwise noted, any test equipment quoted herein and built by Plexus is
warranted to be free from defects in material and workmanship for a period of
ninety (90) days from the date of certification. After the warranty period the
equipment will be repaired on a time and materials basis. Labor will be charged
at the current billing rate. Parts will be charged at cost plus 25%. Travel
expenses will be added to any repairs including travel between Plexus and/or one
of its affiliates. All dedicated test/burn in fixtures will be progress billed
monthly up to 95% of the program cost. The remaining 5% is due upon fixture
certification.

6.   DOCUMENTATION
------------------

Unless Plexus is or has generated the documentation for the Customer as part of
its services to the Customer, then the Customer is responsible for supplying
Plexus with complete documentation. This includes, at a minimum, (three) 3
complete and current sets of documentation including, at a minimum, all prints,
softwares, artwork, and bill of materials with manufacturer and part number, and
any specifications, including test specializations or procedure, called for on
any customer prints. It is the Customer's responsibility to assure that Plexus
receives timely notification of any changes to the documentation, and updated
prints reflecting the changes.

7.   TOOLING
------------

All tooling produced or obtained for the assemblies delivered hereunder and paid
for by Customer shall become and remain the property of Customer at the time
payment in full is received for the tooling by Plexus. Such tooling shall be
used by Plexus only for the benefit of Customer, and shall be delivered to
Customer upon request. If Customer requests the return of any tooling from
Plexus and Plexus determines the return of such tooling prevents Plexus from
providing the assemblies to Customer, then Plexus shall inform Customer in
writing, and Customer and Plexus shall negotiate a mutually acceptable
resolution.

Customer, at its sole discretion, may consign to Plexus, items, including, but
not limited to, materials and/or equipment relating to the production and/or
testing of the assemblies at Plexus' location. The material and/or equipment
shall be utilized by Plexus only for the production and/or testing of the
assemblies. Customer shall assist Plexus in installing the materials and/or
equipment and shall provide training and maintenance instructions, if requested
by Plexus or required by Customer. Customer shall be responsible for repairing,
upgrading, replacing and/or maintaining the materials and/or equipment consigned
to Plexus. However, Plexus shall provide routine maintenance.

8.   TERMINATION AND CANCELLATION OF MANUFACTURING PHASE
--------------------------------------------------------

During the Manufacturing Phase, either party shall have the right to terminate
any or all activities under this agreement for any reason and at any time upon
six (6) months prior written notice to the other party. Plexus agrees to
immediately terminate the specified activity pursuant to this Agreement upon
termination or cancellation. If this entire Agreement is terminated, Plexus
shall complete all existing Customer POs as specified below unless otherwise
specified by Customer. Customer agrees to reimburse Plexus for reasonable and
allowable expenses directly incurred by

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

Plexus including, but not limited to, packaging and related transportation costs
and expenses, and the return to Customer of any Customer owned material(s),
tools, equipment and/or any other related items, consistent with Section A2
Cancellation, above. Customer and Plexus shall negotiate a settlement of any
other reasonable and allowable expenses directly incurred by Plexus.

If this entire agreement is terminated, then Plexus shall:

a)   Deliver to Customer all completed assemblies which conform to the
applicable and then current specifications and requirements; and

b)   Return to Customer, at Customer's expense, all tooling, equipment,
Components and/or Long Lead Time Components, drawings, specifications,
documentations and supplies that are owned by Customer pursuant to the Agreement
(in the event of Plexus' material breach and the failure of Plexus to cure such
breach 60 days after receiving written notice thereof from Customer then Plexus
shall pay for freight costs associated with returning all tooling, equipment,
Components and/or Long Lead Time Components, drawings, specifications,
documentations and supplies that are owned by Customer pursuant to the
Agreement); and

c)   Prepare and submit to Customer an itemized document to include the quantity
of assemblies in the production process.

Plexus shall complete and customer agrees to pay for any work in process and
open purchase orders if so requested by Customer as if no termination notice was
given. Customer further agrees to pay for all material ordered in accordance
with Section A2 above or as otherwise authorized in writing by Customer.

B.   MEDICAL DEVICE PROVISIONS
------------------------------

The terms and conditions set forth in this Section B, Medical Device Provisions,
Section A, Manufacturing Phase, as well as the terms and conditions set forth in
Section C, Standard Terms and Conditions, shall be applicable to this portion of
the Agreement.

Engineering Phase:
------------------

1.   Plexus shall be in substantial compliance with design controls as defined
by its product development medical device quality procedures for the device
designs covered by this contract. Plexus responsibilities under these provisions
include:

a)   contributions to the Device History File (DHF) shall be limited to those
items identified in the deliverables section of the project Proposal and/or
Project Plan;

b)   Contributions to the Design Master Record (DMR) shall be limited to those
items identified in the deliverables section of the project Proposal and/or
Project Plan;

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
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c)   Maintenance of quality system quality records, as defined by Plexus
Technology Group's Document Retention Chart, (e.g., Internal Audit Results, QIP
database, Supplier Records, Management Review Meeting Records, etc.) which are
not provided to the customer.

2.   Customer is responsible for identifying all applicable laws and
regulations, including the Food, Drug and Cosmetic Act, and compliance with
those regulations for all devices covered by this contract.

Manufacturing Phase:
--------------------

1.   Customer is responsible for ensuring that the devices covered by this
contract comply with all applicable laws and regulations, including the Food,
Drug and Cosmetic Act and implementing regulations. Customer responsibilities
under these provisions, include but are not limited to the following:

a)   Establishing the finished device specifications.

b)   Ensuring that governmentally-required marketing authorizations, including
any necessary Food and Drug Administration (FDA) approvals or clearances, have
been obtained.

c)   Determining the content of any label or labeling.

d)   Making any required reports to governmental entities, including but not
limited to Medical Device Reports.

e)   Determining whether any recall or other corrective action is required or
appropriate, and developing, implementing and financing any voluntary or
mandatory recall or corrective action.

f)   Reviewing and approving the quality system prior to production of the
devices.

2.   Plexus will provide Customer ongoing access to its facilities and
procedures for quality assurance related to the devices covered by this
contract. Plexus authorizes Customer to conduct periodic quality systems audits
of the manufacturing processes and quality systems related to this contract.
Plexus will manufacture the devices covered by this contract in accordance with
its procedures for manufacturing components of medical devices or finished
medical devices, as applicable.

3.   Customer will provide Plexus with sufficient information to verify,
calibrate, operate, test and maintain any Customer supplied equipment.

4.   Customer shall be responsible for the software validation of any embedded
product software and the validation of all Customer supplied: (1) test equipment
or test software; (2) production equipment or software; and (3) firmware. Plexus
is responsible for the validation of any Plexus software used in production in,
or as part of the Quality System. The responsibilities described in this section
also apply to any revisions of any software.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

5.   The Customer will provide Plexus with copies of the specifications and
written certification that the validation reports for the items listed in
Section #4 above have been performed prior to the production of the devices.

6.   Customer is responsible for defining and validating the finished device
packaging. The Customer will provide Plexus with written certification that the
packaging validation has been performed prior to the production of the devices.

7.   Plexus is responsible for conducting and documenting corrective and
preventive actions based upon the analysis of the quality data available to
Plexus. Quality data or information known to the Customer, but not provided to
Plexus, shall not be included in the analysis of quality data, and the Customer
shall be responsible for the analysis of data not provided to Plexus.

8.   Any Customer initiated request for change to a specification, method,
process or procedure or customer supplied equipment will be evaluated by Plexus,
and Plexus reserves the right to decline to make such change. Customer is
responsible for verification and/or validation of such changes. Customer shall
reimburse Plexus for any costs Plexus incurs in making and/or implementing such
changes.

9.   Plexus shall notify Customer of significant changes in specifications,
methods, processes or procedures that could affect the quality of the devices
covered by this contract, and, as to any such change, Customer and Plexus shall
decide jointly whether, how and when to implement such change, and who shall be
responsible for verification and/or validation of such changes. Customer and
Plexus shall also decide jointly who will be responsible for the costs
associated with such changes.

10.  The Customer must define any traceability requirements. Plexus is
responsible for implementing the defined manufacturing level traceability
requirements and for ensuring that the appropriate manufacturing level
traceability records and associated records are retained for the duration of the
contract.

11.  Unless otherwise specified in the contract, Plexus is not responsible for
ensuring traceability of the devices covered by this contract after distribution
to the end user(s).

12.  Plexus is responsible for retaining the appropriate manufacturing records
as required. When the contract between Plexus and the Customer terminates,
Plexus shall forward all applicable documentation and records to the Customer,
upon request.

13.  Customer may authorize in writing the release of nonconforming components
or devices covered by this contract. The Customer must assess whether the use of
the nonconforming product will affect any regulatory submittals or requirements,
and accept responsibility therefore.

14.  Customer will promptly provide to Plexus copies of all complaints received
by Customer that refer or relate to an assembly manufactured by Plexus and all
adverse event reports to a governmental entity that refer or relate to an
assembly manufactured by Plexus. Plexus will

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

provide to Customer information regarding any complaints Plexus receives about
the product in which the devices covered by this contract are incorporated.

15.  Sections C.(5) and C.(7) "Liability and Indemnification" & "Compliance with
Regulations and Standards", respectively, both a part of Section C "Standard
Terms and Conditions" of this Agreement is further supplemented to provide that
the indemnification of Plexus will further cover Customers' failure to comply
with applicable laws and regulations, including but not limited to the Food,
Drug and Cosmetic Act and implementing regulations.

C.   STANDARD TERMS AND CONDITIONS
----------------------------------

The terms and conditions set forth in this Section C, STANDARD TERMS AND
CONDITIONS shall be applicable to Section A, Manufacturing Phase, as well as the
terms and conditions set forth in Section B, Medical Device Provisions of this
Agreement.

1.   MUTUAL COOPERATION
-----------------------

Plexus represents that it will pursue the Agreement to the best of its ability
and in the best interest of the Customer, and the Customer represents that it
will cooperate with Plexus in reaching the objectives of the Agreement. Plexus
will appoint a project manager for the duration of the Agreement and will
require the Customer to establish one person to coordinate all activities
through. In the event that the project manager is not operating in the best
interest of the Customer, the Customer shall contact Plexus to discuss Agreement
related concerns and/or complaints.

2.   CONFIDENTIAL INFORMATION
-----------------------------

Plexus and the Customer will use best efforts to prevent the disclosure of any
confidential information, unless specifically instructed otherwise in writing by
the disclosing party, and excepting in such instances where Plexus may be
compelled by law to make disclosures. The mechanisms for controlling and
processing confidential information may be covered under a separate Confidential
Disclosure Agreement (if required).

3.   FORCE MAJEURE
------------------

Plexus shall not be liable for any delay in or failure of performance under this
agreement due to any contingency beyond Plexus' control, including, but not
limited to, an act of God, war, insurrection, fire, riot, strike or labor
dispute, sabotage, act of public enemy, flood, storm, accident, equipment
failure, inability to obtain suitable or sufficient labor or material, laws or
regulations, or any other cause beyond its reasonable control.

4.   INTELLECTUAL PROPERTY RIGHTS
---------------------------------

All patents, copyrights, trademarks, or other rights pertaining to inventions,
developments, or improvements made in the course of the work, and funded by the
Customer, are the property of Customer. Plexus will, upon written direction from
Customer, execute any and all papers and documents prepared or submitted by
Customer as may be reasonably required to transfer or

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

secure to Customer full title and authority over such rights. Plexus will be
compensated by Customer for time and expense as incurred in this obligation at
the then current billing rates for those of its employees necessary for these
purposes.

Customer agrees that it shall assume all responsibility for determining whether
the assemblies to be designed and assembled infringe on any patent, copyright or
trademark, and Customer shall indemnify and hold harmless Plexus from any
liability, including legal costs and expenses, damages and attorney fees arising
from any claim demand or suit, including a claim by Customer, based on
allegations or claims that the assemblies or any design, patent, copyright, or
trademark sought to be obtained or obtained by Customer as a result of this
agreement constitutes an infringement of any patent, trademark or copyright of
the United States or any foreign county.

In the event any such claim or suit is asserted or instituted against Plexus,
Plexus shall promptly notify Customer of the assertion of any such allegation or
claim. Customer shall thereupon assume responsibility for and conduct the
defense of each assertion or suit at its expense, and reasonable information and
assistance for the defense of same shall be provided by Plexus for which Plexus
will be compensated for time and expenses at its then current billing rate.
Plexus shall have the right, at its expense, to be represented in the defense of
any such assertion or suit by counsel of its own selection.

The prices quoted do not include, unless specifically stated otherwise, the cost
for testing and/or submittals for assembly approvals or any annual file
maintenance fee, such as for UL, VDE, CSA or FCC. Plexus will assist Customer in
obtaining such approvals and charge for same services at Plexus' current hourly
billing rate.

5.   LIABILITY AND INDEMNIFICATION
----------------------------------

Plexus will use its discretion to pursue the Agreement in the best interest of
Customer. Plexus will be under no liability to Customer or otherwise for its
choice of methods employed, the character or tests and experiments performed,
the results obtained, nor for the use which shall thereafter be made by Customer
of such results. IT IS UNDERSTOOD THAT OTHER THAN THE WARRANTY SET FORTH IN
SECTION A4, NO OTHER GUARANTEES OR WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED,
ARE GIVEN BY PLEXUS, INCLUDING, BUT NOT LIMITED TO ANY WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. PLEXUS SHALL NOT BE LIABLE
FOR ANY INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS)
SUSTAINED OR INCURRED IN CONNECTION WITH THIS AGREEMENT.

Customer will fully indemnify and hold harmless Plexus from any and all
liability, claims demands, costs and expense arising out of the use,
publication, and/or marketing of the results of the assemblies or test results
provided by Plexus, the functioning of the assemblies or the product(s) which
they are a part of, or any other matter resulting from Plexus' performance under
this Agreement, whether such liability, claims or demands be in the nature of
patent, trademark or copyright infringement, public or product liability,
contract liability, or otherwise during or following the terms of this
Agreement, and Customer shall, at its own expense, defend any and

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

all such actions based thereon and shall pay all attorney's fees and cost and
other expenses arising therefrom.

Plexus will not be liable for errors, or expenses which may be incurred in its
performance of this work which results from the engineering and/or design of the
Assemblies, or from Plexus' reliance upon information, technological records,
sketches, drawings, or prototypes furnished by Customer or Customer's design
engineering firm. Customer will forthwith, during the term of this Agreement,
notify Plexus of any and all information, technology changes, or other facts
relevant to any aspect or phase of the Agreement.

6.   ARBITRATION
----------------

All rights and remedies conferred by this Agreement, by any other instrument, or
by law are cumulative and may be exercised singularly or concurrently. If any
provision of this Agreement is held by any court or governmental agency to be
invalid, such invalidity shall not affect the enforceability of any other
provision(s) hereof. This Agreement and any Purchase Orders issued hereunder
shall be governed by and interpreted in accordance with the laws of the State of
Wisconsin. Unless otherwise agreed to in writing by the parties, any controversy
or claim arising out or relating to this Agreement, or the parties' decision to
enter into this Agreement, or the breach thereof, shall be settled by
arbitration through the American Arbitration Association and in accordance with
the Commercial Arbitration Rules of the American Arbitration Association. The
arbitration proceeding shall be conducted and presided over by a single neutral
arbitrator chosen pursuant to American Arbitration Association procedures.
Decision of the arbitrator shall be final, binding, and not subject to appeal or
review; provided that, either party may request that the arbitrator review and
reconsider his or her decision, in whole or in part. Judgment upon the award
rendered by the arbitrator may be entered in any court having jurisdiction
thereof. The arbitration shall be held in Neenah, Wisconsin and the arbitrator
shall apply the substantive law of Wisconsin except that the interpretation and
enforcement of this arbitration provision shall be governed by the federal
Arbitration Act. The arbitrator shall not award either party punitive damages
and the parties shall be deemed to have waived any right to such damages.

7.   CONSENT TO JURISDICTION AND APPLICABLE LAW
-----------------------------------------------

The parties hereby irrevocably submit to the jurisdiction of the courts of the
State of Wisconsin in any action or proceeding arising out of or relating to
this Agreement, and the parties hereby irrevocably agree that all claims in
respect of such action or proceeding may be determined by such courts. The
parties hereby waive, to the fullest extent possible, the defense of an
inconvenient forum to the maintenance of such action or proceeding, and the
parties agree that a final judgement in any action or proceeding shall be
conclusive and may be enforced in other jurisdictions by suit on the judgement
or in any other matter provided by law.

The parties hereby agree that this Agreement shall be governed by and will be
construed in accordance with the laws of the State of Wisconsin, irrespective of
the conflicts of laws provisions thereof.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

8.   NO RECRUITING
------------------

Plexus and the Customer agree that during the term of this program and for
twelve (12) months thereafter, it shall not solicit or recruit (even though
professional recruiters) the employees of the other. This shall not preclude an
employee of either Plexus or the Customer from independently pursuing and
securing employment opportunities with the other on such employee's own
initiative.

9.   ENTIRE AGREEMENT
---------------------

This Agreement, along with the Proposal and/or Project Plan, and Confidential
Disclosure Agreement and/or quotation (if any) and Plexus' invoices, contains
the entire understanding of the parities pertaining to the subject matter
hereof, and no other agreements, oral or otherwise, shall be deemed to exist or
to bind the parties. Notwithstanding anything to the contrary contained herein,
the parties hereto agree that the terms and conditions set forth herein and in
Plexus' invoices, Proposal and/or Project Plan and Confidential Disclosure
Agreement (if any), shall supersede any and all terms and conditions submitted
by the Customer in any document, including but not limited to any terms and
conditions contained in the Customer's purchase order. This agreement may not be
modified or terminated orally, and no claimed modification, termination, or
waiver shall be binding unless in writing and signed by both parties.

Accepted and agreed to:

<TABLE>
<CAPTION>
RITA MEDICAL SYSTEMS, INC.                             PLEXUS CORP.
<S>                                                    <C>
                                                       ENGINEERING AUTHORIZATION:

By: /s/ Barry Cheskin                                  By: /s/
    ----------------------------------------               -------------------------------------

Title: President and Chief Financial Officer           Title: Vice President of Engineering
       -------------------------------------                  ----------------------------------

Date: February 24, 2000                                Date: February 17, 2000
      --------------------------------------                 -----------------------------------



                                                       MANUFACTURING AUTHORIZATION:

                                                       By: /s/ Don Reid
                                                           -------------------------------------

                                                       Title: Vice President and General Manager
                                                              ----------------------------------

                                                       Date: February 17, 2000
                                                             -----------------------------------
</TABLE>

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

                Attachments to Professional Services Agreement

Attachment A    Document Change Control Agreement

Attachment B    Project Plan (subject to revision upon mutual agreement)

Attachment C    Unit Cost Calculation to be used for Planning Purposes

Attachment D    Specification (subject to revision upon mutual agreement)

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

<TABLE>
<S>                                         <C>                                      <C>            <C>
[LOGO HERE]                                 Plexus Corporation                       Quote #          0
The Product Realization Company             2121 Harrison Street
                                            Neenah, WI 54957-0529                    Date:          2/28/00
                                            (920) 722-2826  Fax (920) 720-6700
================================================================================================================
Company:      Rita Medical Systems                                Project Name:      Ablation System
              967 N. Shoreline Blvd.                              Assembly #:        Model 1500
              Mountain View, CA                                   Assembly Rev:      N/A
                                                                  Assembly Name:
Attention:    Ron Steckel                                         Prepared by:       John Grein
cc:                                                               Phone:             425-398-2825
</TABLE>

<TABLE>
UNIT COST INFORMATION
<S>                                                    <S>             <C>             <C>             <C>
                                                   -------------------------------------------------------------
Estimated Annual Quantity                              [***]           [***]           [***]           [***]
                                                   -------------------------------------------------------------
Estimated Release Quantity                             [***]           [***]           [***]           [***]
                                                   -------------------------------------------------------------

I.        MATERIALS                                    [***]           [***]           [***]           [***]
II.       PCBA LABOR                                   [***]           [***]           [***]           [***]
III.      FINAL ASSY. LABOR                            [***]           [***]           [***]           [***]
IV.       ICT TEST                                      N/A             N/A             N/A             N/A
V.        FUNCTIONAL TEST                               Inc.            Inc.            Inc.            Inc.
VI.       RUN IN TEST                                   Inc.            Inc.            Inc.            Inc.
VII.      PACKAGING                                     Inc.            Inc.            Inc.            Inc.
                                                   -------------------------------------------------------------
VIII.     TOTAL                                        [***]           [***]           [***]           [***]
                                                   -------------------------------------------------------------
INVENTORY CARRY/MONTH                                  [***]           [***]           [***]           [***]
</TABLE>
See Note 3

     Notes
     -----
1.   ICT Test is not included.  PCBA design does not support ICT.
2.   Functional PCBA, System Test, Ambient Run-in Test, Electrical Safety, and
     Final Testing Inc. in Final Assy Labor.
3.   Inventory Carrying Cost/Month is based on purchasing [***] in material for
     Initial PO of [***] units. On initial PO of less than [***] units a
     carrying charge of [***] will apply from date of last shipment on Initial
     PO to date of first shipment on next PO.

NON-RECURRING CHARGES

A.   PCB TOOLING                                   [***]
B.   PCB ETF                                       [***]
C.   ICT FIXTURE                                    N/A
D.   FUNCTIONAL FIXTURE                            [***]
E.   PCBA PROCESS DEVELOPMENT                       N/C
F.   XRAY TOOLING                                   N/A
G.   SMT PROGRAMMING                                Inc.
H.   SMT STENCIL (S)                                Inc.
I.   AUTO-INSERT PROGRAMMING                        N/A
J.   CONFORMAL COATING PROG.                        N/A
K.   MANUFACTURING SETUP                           [***]
L.   OTHER                                         [***]

SPECIFIC ASSEMBLY NOTES AND ASSUMPTIONS

A.   See Previous Proposal Dated January 12, 2000.
B.   Final Assembly Labor is Estimated Within +/- 15%.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.
<PAGE>

C.   Current PCB Supplier is Capable of Meeting Plexus Production Requirements.
D.   PCBA process development costs up to [***] will be paid by Plexus. Rita
     Medical responsible for additional costs due
E.   to design costs.
F.
G.
H.

*** Material has been omitted pursuant to a request for confidential treatment
and such material has been filed separately with the SEC.