HYDG.L Regulatory News (HYDG)

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

Opsec Security Group Plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

P

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation: iii

Herald Investment Management Limited

4. Full name of shareholder(s)  (if different from 3.):iv

Discretionary investment management clients of Herald Investment Management Limited

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

30th September 2015

6. Date on which issuer notified:

2nd October 2015

7. Threshold(s) that is/are crossed orreached: vi, vii

25%,24%,23%,22%,21% 20%, 19%,18%,17%,16%,15%,14%,13%,12%,11%,

10%,5%

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Indirect

Direct xi

Indirect xii

Direct

Indirect

GB0000462191

30,512,078

30,512,078

None

None

0.00%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

None

Nil

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

None

Nominal

Delta

Nil

Total (A+B+C)

Number of voting rights

Percentage of voting rights

None

0.00%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxi

N/A

Proxy Voting:

10. Name of the proxy holder:

N/A

11. Number of voting rights proxy holder will cease to hold:

N/A

12. Date on which proxy holder will cease to hold voting rights:

N/A

13. Additional information:

14. Contact name:

Andrew Miller CFO

15. Contact telephone number:

020 7553 6308

Note: Annex should only be submitted to the FCA not the issuer

Annex: Notification of major interests in share

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

Herald Investment Management Limited

Contact address

(registered office for legal entities)

10/11 Charterhouse Square

London EC1M 6EE

Phone number & email

020 7553 6308

Other useful information

(at least legal representative for legal persons)

Andrew Miller CFO

B: Identity of the notifier, if applicable

Full name

See above

Contact address

Phone number & email

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information

To calculate the percentage of voting rights held we have used the figure announced to the market by the company via RNS on 31st March 2014 of 121,212,121 total equity shares in issue confirmed via RNS on 30th September 2015 as consisting of 101,212,121 ordinary shares and 20,000,000 redeemable convertible preference shares.

For notes on how to complete form TR-1 please see the FCA website.