Due to many request, Heinie Specialty Products, Inc., has introduced the "Ledge". This is a modification of the popular SlantPro Ultra Low Mount Sight. This modification allows the operator to cycle the slide with one hand much easier. The outer edges have been left square to bite into whatever material is being used for cycling.FeaturesDesigned for easy one hand cyclesQWIK notch width of .156"Rear sight serrations help eliminate light glareNotch Width: .156"