Traditional high security Yale Nightlatch approved to British Standard BS 8621:2007 and Police Secure by Design Automatic deadlock locks when closing the door for instant security and latch can be held back temporarily with snib button High security TS007 1 star Rim Cylinder with reinforced exterior for anti-drill protection and components designed to resist known attack methods Internal nightlatch handle can be locked from the inside with a key, ideal for use with wooden doors with glazed panels Supplied with 2 standard Yale keys and fixing pack for easy installation Anti-card slip protection, prevents your lock from being vulnerable to this technique that only requires a card sized piece of plastic