The USM is a Universal Handgun Scope Mount which requires no modification to the gun and offers a steady and secure mounting platform over the slide. It is constructed of extremely durable 6061-T6 billet aluminum with a matte hard coat anodized finish and quick and easy single bolt installation. The mount facilitates prompt sight alignment, adds a front underside accessory rail in place of the original and allows the original sights remain operational. The USM is compatible with 1913 MIL-STD picatinny rail based optics and all handguns with underside accessory rail with a minimum of 1.7" long & sights up to 1.8" in standard height