Document:

EX-10.10

                                LOCK-UP AGREEMENT

                                                                   May ___, 2004

PAULSON INVESTMENT COMPANY, INC.
As Representative of the several
Underwriters named in Schedule I to
the Underwriting Agreement referred to below
811 SW Naito Parkway, Suite 200
Portland, Oregon  97204

                    Re:   SMARTPROS LTD. - PUBLIC OFFERING

Ladies and Gentlemen:

              The undersigned understands that you, as Representative of the
several Underwriters, propose to enter into an Underwriting Agreement (the
"UNDERWRITING AGREEMENT") with SmartPros Ltd., a Delaware corporation (the
"COMPANY"), providing for the public offering (the "PUBLIC OFFERING") by the
several Underwriters to be named in Schedule I to the Underwriting Agreement
between you and the Company (the "UNDERWRITERS"), of Units ("UNITS"), each Unit
consisting of two shares of Common Stock, par value $0.0001, of the Company
("COMMON STOCK") and one Common Stock purchase warrant, all as more fully
described in the Prospectus (defined below).

              In consideration of the Underwriters' agreement to purchase and
make the Public Offering of the Units, and for other good and valuable
consideration receipt of which is hereby acknowledged, the undersigned hereby
agrees that, without the prior written consent of Paulson Investment Company,
Inc. on behalf of the Underwriters, the undersigned will not, during the period
ending one year after the date of the prospectus relating to the Public Offering
(the "PROSPECTUS"): (1) offer, pledge, announce the intention to sell, sell,
contract to sell, sell any option or contract to purchase, purchase any option
or contract to sell, grant any option, right or warrant to purchase, or
otherwise transfer or dispose of, directly or indirectly, any shares of Common
Stock, or any securities of the Company that are substantially similar to the
Common Stock, or any securities convertible into or exercisable or exchangeable
for Common Stock (including, but not limited to, Common Stock which may be
deemed to be beneficially owned by the undersigned in accordance with the rules
and regulations of the Securities and Exchange Commission and securities which
may be issued upon exercise of a stock option or warrant); or (2) enter into any
swap, option, future, forward or other agreement that transfers, in whole or in
part, any of the economic consequences of ownership of the Common Stock or any
securities of the Company which are substantially similar to the Common Stock,
including, but not limited to, any security convertible into or exercisable or
exchangeable for Common Stock, whether any such transaction described in clause
(1) or (2) above is to be settled by delivery of Common Stock or such other
securities, in cash or otherwise. In addition, the undersigned agrees that,
without the prior written consent of Paulson Investment Company, Inc. on behalf
of the Underwriters, it will not, during the period ending one year after the
date of the Prospectus, make

                                       1
<PAGE>

any demand for or exercise any right with respect to, the registration of any
shares of Common Stock or any substantially similar securities of the Company,
including but not limited to, any security convertible into or exercisable or
exchangeable for Common Stock.

              The undersigned represents and warrants that it is not a party to
any agreement or understanding that would cause a breach of this Lock-Up
Agreement if it were entered into during the period in which the restrictions
set forth herein are effective.

              In furtherance of the foregoing, the Company and any duly
appointed transfer agent for the registration or transfer of the securities
described herein are hereby authorized to decline to make any transfer of
securities if such transfer would constitute a violation or breach of this
Lock-Up Agreement.

              The undersigned hereby represents and warrants that the
undersigned has full power and authority to enter into this Lock-up Agreement.
All authority herein conferred or agreed to be conferred and any obligations of
the undersigned shall be binding upon the successors, assigns, heirs or personal
representatives of the undersigned.

              The undersigned understands and you have agreed that this
agreement shall immediately terminate and the undersigned shall be released from
all his obligations hereunder if the Public Offering has not been consummated by
May_, 2005; PROVIDED, HOWEVER, if the Company withdraws the registration
statement relating to the Public Offering before it becomes effective or if you
notify the Company that you are no longer prepared to act as an underwriter in
connection with the Public Offering before the registration statement related to
the Public Offering becomes effective, then this agreement shall immediately
terminate and the undersigned shall be released from all his obligations
hereunder immediately upon the date of such withdrawal or notification, as the
case may be.

              The undersigned understands that the Underwriters are entering
into the Underwriting Agreement and proceeding with the Public Offering in
reliance upon this Lock-Up Agreement.

                                       2
<PAGE>

       THIS LOCK-UP AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF OREGON, WITHOUT REGARD TO THE CONFLICT OF LAWS
PRINCIPLES THEREOF.

                                       Very truly yours,

                                       -----------------------------------------

                                       By:                                   (1)
                                          --------------------------------------
                                          Name:
                                          Title:

Accepted as of the date
first set forth above:

PAULSON INVESTMENT COMPANY, INC.

     Acting severally on behalf of themselves and
     the several Underwriters to be named in
     Schedule I to the Underwriting Agreement

By:
     ----------------------------------------------
     Name:
     Title:

# 1748472_v1

--------
(1)  To be completed by if entity other than an individual.

                                       3<PAGE>

                                                                     EXHIBIT 4.1

                NOT VALID UNLESS COUNTERSIGNED BY TRANSFER AGENT
                   INCORPORATED UNDER THE LAWS OF THE STATE OF

                                     Nevada

            NUMBER                                                  SHARES
                            XENONICS HOLDINGS, INC.

                                                            CUSIP NO.984117 10 1

                   AUTHORIZED COMMON STOCK: 20,000,000 SHARES
                                PAR VALUE: $.001

THIS CERTIFIES THAT

IS THE RECORD HOLDER OF

                 Shares of XENONICS HOLDINGS, INC. Common Stock

transferable on the books of the Corporation in person or by duly authorized
attorney upon surrender of this Certificate properly endorsed. This Certificate
is not valid until countersigned by the Transfer Agent and registered by the
Registrar.

          Witness the facsimile seal of the Corporation and the facsimile
signatures of its duly authorized officers.

                  Dated:

[XENONICS HOLDINGS, INC. SEAL]    [ILLEGIBLE]         /s/ Jeffrey P. Kennedy
                                  ----------------    ------------------------
                                  CHAIRMAN            PRESIDENT

                                                 COUNTERSIGNED & REGISTERED

<PAGE>

The following abbreviations, when used in the Inscription on the face of this
certificate, shall be construed as though they were written out in full
according to applicable laws or regulations.

TEN COM - as tenants in common             UNIF GIFT MIN ACT_____Custodian______
TEN ENT - as tenants by the entireties                      (Cust)       (Minor)
JT TEN  - as joint tenants with right of          under Uniform Gifts to Minors
          survivorship and not as tenants         Act___________________________
          in common                                           State

         Additional abbreviations may also be used though not in the above list.

      For Value Received,________________ hereby sell, assign and transfer unto

      PLEASE INSERT SOCIAL SECURITY OR OTHER
           IDENTIFYING NUMBER OF ASSIGNEE

________________________________________________________________________________
   (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS,INCLUDING ZIP CODE, OF ASSIGNEE)

________________________________________________________________________________

________________________________________________________________________________

__________________________________________________________________________Shares

of the capital stock represented by the within certificate, and do hereby
irrevocably constitute and appoint

________________________________________________________________________Attorney
to transfer the said stock on the books of the within named Corporation with
full power of substitution in the premises.

Dated_________________________________

      NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS
              WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR
              WITHOUT ALTERATION OH ENLARGEMENT OR ANY CHANGE WHATEVER

-     NOTICE SIGNATURE GUARANTEED:

SIGNATURE(S) MUST BE GUARANTEED BY A FIRM WHICH IS A MEMBER OF A REGISTERED
NATIONAL STOCK EXCHANGE, OR BY A BANK (OTHER THAN A SAVINGS BANK). OR A TRUST
COMPANY. THE GUARANTEEING FIRM MUST BE A MEMBER OF THE MEDALLION GUARANTEE
PROGRAM.

      TRANSFER FEE WILL APPLY

                  * * * FOR MEDALLION GUARANTEE USE ONLY * * *

                                [SPECIMEN LOGO]

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00068-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00068-of-00352.parquet"}]]