This sliding patio door lock is constructed of cast zinc and it comes in a white painted finish. This lock is DESIGNED FOR USE ON VINYL SLIDING PATIO DOOR SYSTEMS, yet it may also work with some horizontal and vertical sliding (single hung) windows, depending upon the type of vinyl liners and balances used to construct the windows. Note: These locks may also fit many horizontal vinyl sliding windows and some vertical sliding windows, but not all of them. These locks feature an adjustable jaw that has a "vise-like" grip, and they are capable of opening up to 7/8 in. wide 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 1/16 in. to 7/8 in. thick. This lock can be used as a secondary lock when the door or window is shut, and to provide security during minimal opening for ventilation.