Exhibit 4.11

Translation
of the notarised version 11 March 2003

Today
appeared the following persons before me the undersigned Notary

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ----------------------------------------------------------------------------------------------------- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|1.                                                                                                                                                                                                                                                                                                                                                                                                       |  | Dr. Björn-Axel Dißars, lawyer (* 14 March 1967), with his offices at Warburgstrasse 50, 20354 Hamburg
|acting not on behalf of himself but pursuant to the power of attorney granted him, a certified copy of which is attached to this Agreement, on behalf of Spirent GmbH, a private limited company under the laws of Germany, registered in the commercial
register of the local court in Elmshorn under registration number HRB 1948 and with headquarters at Grosser Moorweg 45, 25436 Tornesch, Germany
|                                                                                                                                                                                                                                                                                                                                                                                                         |  |                                                                                                       |  | (the "Seller");                                                                                                                                                                                                                                                                
|2.                                                                                                                                                                                                                                                                                                                                                                                                       |  | a)                                                                                                    |  | Mr Wolfgang Hohorst (* 24 March 1935), Schilfgrund 13, 32429 Minden                                                                                                                                                                                                            
|                                                                                                                                                                                                                                                                                                                                                                                                         |  | b)                                                                                                    |  | Mr. Sven-Michael Hohorst (* 5 March 1963), Artilleriestrasse 5a, 32427 Minden                                                                                                                                                                                                  
|acting not on behalf of themselves but on behalf of                                                                                                                                                                                                                                                                                                                                                     
|                                                                                                                                                                                                                                                                                                                                                                                                         |  | a)                                                                                                    |  | Hohorst Familien Holding (Minden) Beteiligungs GmbH, a private limited company under the laws of Germany, registered in the commercial register of the local court in Minden under the registration number HRB 2913 and with its headquarters at
Hansastrasse 27, 32423 Minden 
|                                                                                                                                                                                                                                                                                                                                                                                                         |  |                                                                                                       |  | (the "Purchaser 1");                                                                                                                                                                                                                                                           
|                                                                                                                                                                                                                                                                                                                                                                                                         |  | b)                                                                                                    |  | Hohorst Familien Holding (Schweiz) Beteiligungs GmbH, a private limited company under the laws of Germany, registered in the commercial register of the local court in Minden under the registration number HRB 2914 and with its headquarters at
Hansastrasse 27, 32423 Minden
|                                                                                                                                                                                                                                                                                                                                                                                                         |  |                                                                                                       |  | (the "Purchaser 2"),                                                                                                                                                                                                                                                           
|(Purchaser 1 and Purchaser 2 jointly the "Purchasers").                                                                                                                                                                                                                                                                                                                                                 

The
person appearing as per 1 above identified himself by presenting his valid identification papers The persons appearing as per 2 a) and b) above are personally known to the Notary.

As
far as this Contract contains English language provisions, the Notary convinced himself that the person appearing are able to sufficiently understand English. The Notary stated that he is able to
sufficiently read and understand English.

The
Notary asked the persons appearing whether, unless instructed by all parties jointly, he, besides his official duty as a notary, or any other person being a member of his professional partnership
was already involved in the matter being the subject of this recording. The Parties declared that this was not the case.

The
Parties asked for recording of the following

SHARE SALE AND PURCHASE AGREEMENT

They
stated:

PREAMBLE

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THEREFORE,
the Seller and the Purchasers (collectively the "Parties") agree as follows:

The
Seller hereby transfers Share 1 to Purchaser 1 and Purchaser 1 accepts such transfer.

The
Seller hereby transfers Share 2 to Purchaser 2 and Purchaser 2 accepts such transfer.

The
transfer of the Shares to the Purchasers is subject to the following conditions precedent (the "Conditions Precedent") having been satisfied.

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Account no.:

37859466Type of Account:

Euro AccountBank (the "Bank"):

HSBC International DivisionLondonSort Code (BLZ):

40-05-15Swift Code:

MID LGB 11Beneficiary:

Spirent plc.


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The
notarisation was interrupted at 9.00 pm, started again on 9.40 pm, was again interrupted at 11.35 pm and started again at 11.50 pm. Thereafter this protocol and its exhibits were read by the
Notary to the persons appearing and were accepted and signed by them as follows:

|                                                     |  |                     
|---------------------------------------------------- |  | --------------------
|Spirent B.V.
By:                                     |  |                     
|                                                     |  |                     
|Dr. Björn-Axel Dißars                               
|Hohorst Familien Holding (Minden) Beteiligungs GmbH 
|By:                                                  |  |                     
|                                                     |  |                     
|Wolfgang Hohorst                                     |  | Sven-Michael Hohorst
|Hohorst Familien Holding (Schweiz) Beteiligungs GmbH
|By:                                                  |  |                     
|                                                     |  |                     
|Wolfgang Hohorst                                     |  | Sven-Michael Hohorst

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Exhibit 1.2

Approval of WAGO Kontakttechnik GmbH

WAGO Kontakttechnik GmbH hereby irrevocably approves the split of the share of € 5,100,000 held by Spirent GmbH into two shares of
€ 3,100,000 and € 2,000,000 and the sale and transfer of the partial share of € 3,100,000 to Hohorst Familien
Holding (Minden) Beteiligungs GmbH and of the partial share of € 2,000,000 to Hohorst Familien Holding (Schweiz) Beteiligungs GmbH.

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Exhibit 2.1 (d)

Guarantee payable on first demand

[Letterhead
of Spirent plc.]

Guarantee

Spirent
GmbH, a private limited company under the laws of Germany, registered in the commercial register of the local court in Elmshorn under registration number HRB 1948 and with headquarters at
Grosser Moorweg 45, 25436 Tornesch, Germany (the "Seller");

and

Hohorst
Familien Holding (Minden) Beteiligungs GmbH, a private limited company under the laws of Germany, registered in the commercial register of the local court in Minden under the registration
number HRB 2913 and with its headquarters at Hansastrasse 27, 32423 Minden (the "Purchaser 1");

and

Hohorst
Familien Holding (Schweiz) Beteiligungs GmbH, a private limited company under the laws of Germany, registered in the commercial register of the local court in Minden under the registration
number HRB 2914 and with its headquarters at Hansastrasse 27, 32423 Minden (the "Purchaser 2"),

(Purchaser
1 and Purchaser 2 jointly the "Purchasers").

have
entered into an agreement for the sale and transfer of shares in WAGO Kontakttechnik GmbH (the "Agreement")

We,
Spirent plc, hereby give a guarantee ("Bürgschaft") to the Purchasers, being joint and several creditors, for all claims for payment
that the Purchasers may have against the Seller under the Agreement.

This
guarantee is limited to an amount of € 82,988,410.00.

This
guarantee is payable on the Purchasers' first written demand specifying the amount and legal cause of the Purchasers' claim against the Seller and stating that the Seller has failed to comply
with its payment obligation in respect thereof.

This
guarantee shall expire when this document is returned to us by or with the consent of the Purchasers or on 11 March 2033, whichever occurs earlier, unless a demand for payment
hereunder, complying with the provisions of the preceding paragraph, has been received by us on or before that date.

This
document shall be returned to us immediately upon expiry of our guarantee.

Any
rights or obligation arising out of this guarantee may only be transferred to a third party with our prior written consent; Section 354a German Commercial Code remains unaffected. We hereby
explicitly and irrevocably agree to a transfer of rights hereunder to Dresdner Bank AG.

This
guarantee shall be subject to German law. Any disputes arising out of or in connection with this guarantee shall be settled by arbitration in accordance with the UNCITRAL Arbitration Rules in
effect on the date hereof. The appointing authority shall be the President of the Hamburg Court of Appeals (Präsident des Oberlandesgerichts in
Hamburg). The number of arbitrators shall be three. The place of arbitration shall be Hamburg. The language that may be used in the arbitral proceedings shall be German or
English.

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In
the event that any provision of this guarantee should be ineffective, this shall not affect the validity of the remainder hereof.

This
guarantee is subject to and shall be governed in accordance with German law.

|             |  |             
|------------ |  | ------------
|[...], [...] |  |             
|             |  |             
|             |  | Spirent plc.
|             |  | by:         

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Exhibit 2.1 (e)

WAGO Contact Agreement

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Exhibit 2.1 (f)

WAGO Holding Agreement

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Exhibit 2.1 (g)

WAGO Verwaltungs Agreement

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Exhibit 2.1 (h)

Form of Legal Opinion

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Exhibit 2.1 (i)

Confirmation of Spirent

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Exhibit 6.2

Pension Schedule

1      Definitions



2      Transitional Period of Participation



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Exhibit 7

List of Affiliates

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