This vinyl patio sliding door lock is constructed of diecast and comes in a white painted finish. These locks feature an adjustable jaw that has a "vise-like" grip, and they are capable of opening up to 7/8 in. W for a secure, non-marring hold on thick vinyl rails. When installing this lock, the cam style locking lever should be rotated hand-tight over the rail or vinyl edge to a sufficient torque prior to locking down the lever. This lock can be adjusted to fit on rail thicknesses ranging from 1/4 in. to 7/8 in. thick. This lock can be used as a secondary lock when patio door is shut, and to secure an open door during ventilation. This item is also used by many on vertical and horizontal vinyl sliding windows. No tools are required for the installation of this lock.