These sliding patio door locks are keyed for extra security to help prevent unwanted opening of a patio sliding door from either side. The durable housings of these locks are constructed of diecast metal and they feature solid steel locking bolts that extend and retract and lock into place. The security benefits of these locks help to prevent prying and lifting of the active panels, significantly reducing the chances of entry from the outside. Each set includes two sets of keys, installation hardware and instructions, and they can be installed with a few simple tools.