Ade Advanced Optics Ultra Compact Pistol Class 3R Green Laser Gun Sight with Quick Release Weaver Mount, Black Fits all Railed weapons weaver/picatinny; Some weapons may require an adapter like H&K and Sigma series pistols, some sig sauer pro series Very compact and light Aluminum Construction; 532nm Green Laser Beam &lt;5mw Quick Release System Attaches to Most Weaver Style/Picatinny Rails Fully Adjustable Laser for Windage and Elevation Operates with a single CR2 battery(included)