Dale Nickel Plated 3L Mortice Sash Lock is designed for using to easily keep a door securely shut. The mortice lock is embedded within the door and the sash lock provides a latch and a bolt. The door can be opened and closed from the outside without needing a key. The 3 levers provide minimum security so the lock is ideal for using on back or internal doors. The nickel plating provides a decorative finish that is corrosion resistant.