High quality material: Sliding patio lock is made of high quality zinc alloy. Better corrosion inhibitor and better wear resistance. 2 Pieces children's window door lock:This is a sliding patio door lock, set the window bolt safety lock to avoid accidentally opening the window, provide extra security for your children and windows, it is recommended to install the lock at the top and bottom for maximum security, home security system upgrade With key: each sliding terrace window lock comes with 2 keys (keys are universal) Easy to install: Sliding patio window locks come with screws, so you just 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.