1、SECURITY LOCK: The 3 inch door security lock is designed to withstand up to 800lbs of internal door opening force. It helps prevent doors from being kicked open. Increase your home security and keep your family safe. 2、EASY TO USE: To unlock the door, pinch the top and bottom locks. Then slide the lock sideways along the door toward the hinges until it can be pulled outward. 3、CHILDREN'S LOCK: Door safety locks add extra security for children by preventing opening the door to strangers. Please install it higher than the door handle that is out of touch of children, e.g. at the top of the door. 4、UNIQUE DESIGN: Features a spring loaded, child proof and tamper resistant design with a slippy sandblasted oxidized finish. 5、ALUMINUM ALLOY: Premium aluminum material provides higher security against unauthorized access than traditional locks.