High security, insurance sash locks. Recommended for back door security. The Chubb 3U74 5 Lever Sashlock will replace most other lever operated mortice sashlocks with minimum alteration to the door. Pierced to accept bolt through furniture. Deadbolt is locked or unlocked by key from either side. Reversible latchbolt withdrawn by lever handle from either side. Mechanism: 5 Lever