The Trijicon MRO Co-Witness Mount is one of the smoothest functioning QD lever on the market! Superior clamping that will not damage or coin the rail surface. Extremely smooth in operation with a multi-facetted adjustment nut to get the exact tension required by the operator. Fully adjustable with no tools required, can be adjusted to fit rails not machined to mil-spec tolerances. Weighs only 2.0 oz. Precision machined for optimum return to zero performance and reliability Hard coat anodized 6061 aluminum for a lifetime of service Patented QD lever by Elite Defense 100% made in the U.S.A. with MI Lifetime Warranty Mfg: Midwest Industries