High quality material: The sliding patio lock is made of high quality zinc alloy. Better corrosion inhibitor and wear resistance. 2pcs Child Window Door Lock: This is a sliding patio door lock, set the bolt safety lock window lock to avoid accidentally opening the window, provides extra security for your children and your windows, it is recommended to install the lock at the top and bottom for maximum security, home security system upgrade > With key: Each sliding patio window lock comes with 2 keys (the keys are universal) Easy to install: The sliding patio window locks come with screws, it so you just need to drill and install. Widely used: This universal sliding patio lock product is suitable for most hinged or sliding doors and windows. Perfect for homes, schools and other children's locations. Features: Material: zinc alloy + iron + copper Total length: 40 mm Distance between screw holes: 13 mm Lock projection length: 10 mm White color Quantity: 2 pieces Packing list: 2 x sliding door locks 4 x keys 8 x stainless steel screws