This Defender Security door and window lock is constructed of diecast material and comes in a white-painted color. It can be used on sliding doors and old-style windows that have raised metal fins, no wider than 1/4 in. The lock is designed as a secondary security locking devise for your sliding door, which can be used in both the closed-door, or slightly-opened for ventilating position, as well as to help keep children from accidentally opening it. 2 tamper-resistant, double hex security screws and a wrench are included with this lock. This lock can also be used with older style metal-framed sliding windows.