The Midwest Industries Aimpoint ACRO QD mount features superior clamping that won't damage or mar the rail surface. It operates very smoothly, with a multi-faceted adjustment nut to achieve the exact tension needed by the user. Fully adjustable without tools, it can fit rails that are not machined to mil-spec tolerances. It also has the smoothest functioning QD lever on the market, patented by Elite Defense. RSR -