This aluminum patio door handle is a surface with clamp latch style. Often found on older style patio doors, it is mounted on the door's inside frame and the clamp latch latches onto an extrusion (astragal) on the jamb. It has 2 inch handle height extruded aluminum inside handle. The clamp has a 1/4 inch profile and 1/2 inch projection when in locked position. To key this unit use Prime-Line part E 2071.