Osprey red laser c/w rail mount incredibly light weight [ 12 oz.] integral picatinny rail system allows a wide variety of accessories to be stacked below laser system. 5 m/w laser with 632 n/m strength allowing for the brightest red laser available on the market.  Fully adjustable and mount to Weaver® style / Picatinny accessory rail. Has its own built-in lower rail that can accommodate a flashlight or any other accessory you need. Measures 2 1/4 x 7/8". Weighs 1 oz. Lifetime Warranty