This Prime-Line E 2171 Steel Round-Faced Mortise Latch with Vertical Keyway Lock has a rounded-end, steel face plate. This mortise lock has a built-in feature that if the hook latch is extended and you close your door it will automatically retract rather than damage your door, jamb or the spring in this mortise lock. The keyway stands in a vertical position with hook fully extended when in the locked position. The hook projection of the sliding door lock is easily adjustable with the turn of a screw. For use on patio sliding doors constructed of both wood and vinyl materials. Easily install this replacement latch with a few simple tools. Made of steel construction, the latch replacement comes finished in silver and is strong, durable, and made to last. The patio door mortise lock has mounting holes 2-9/16 inch on center and a 1000lb strength. Refer to the line art drawing and compare with your needs before purchasing (not universal).