This Yale BS2 British Standard Nightlatch is designed for high security and is approved by insurance companies. It features an automatic deadlock that locks when the door is closed, providing instant security. The latch can be temporarily held back using the snib button. The nightlatch includes a high-security TS007 1-star rated Rim Cylinder with a reinforced exterior for enhanced anti-drill protection and components engineered to resist known attack methods. The internal nightlatch handle can be locked from the inside with a key, making it ideal for use with wooden doors that have glazed panels. The package contains two standard Yale keys and a fixing pack for straightforward installation. It also incorporates anti-card slip protection, preventing common vulnerabilities that only require a card-sized piece of plastic. This model has a 40 mm backset.