LOCK No. 23
This lock is used on Telephones No's 706 and 710. It fits between the handset rests.
The lock is used to stop people using the phone for outgoing calls. Once the lock is switched to the off position calls can be made.
Used in conjunction with the Dial No. 28, which allows 999 calls to be
made when the lock is switched on.
Last revised: February 18, 2018