Yale P-1-BLX-PB-60 Double Locking Nightlatch, 60 mm Backset, Brass Finish, High Security, can be Locked from Inside with Key by Amazon.co.uk

• Traditional high security Yale nightlatch with convenient lever handle to operate lock inside the property

• Automatic deadlock is engaged when you close the door for instant security and latch bolt can be held back temporarily with snib button

• Includes Yale rim cylinder operated by key from the outside with standard security components

• Internal nightlatch handle can be locked from the inside with a key, ideal for use with wooden doors with large glazed panels

• Supplied with two standard Yale keys and fixing pack

• Anti-card slip protection, prevents your lock from being vulnerable to this specialist technique that only requires a credit card sized piece of plastic