This is a tilt latch, spring-loaded, wrap around design. Used on single or double hung aluminum windows, and attaches to the top rail and stile. It is injected molded black plastic, with fasteners. Made for tilt out windows. Dimensions are 2-1/4 in. in length, 3/4 in. width. The mounting holes are 1-11/16 in. on center, with a 15/16 in. leg drop down, and 3/8 in. backset. Used on BetterBilt windows, 1 left-hand, 1 right-hand per package.