A deadlatch is a type of lock that can only be opened by a key from the outside or a thumb turn from the inside.

Deadlatches offer a high level of security because they cannot be opened by force or manipulation.

There are various types of deadlatches available, including single-cylinder deadlatches, double-cylinder deadlatches, and keyed deadbolts.

Installing a deadlatch requires proper preparation and tools. Ensure you follow the manufacturer's instructions carefully.