Ade Advanced Optics Compact Class 3R Red Laser Sight with Detachable Remote Pressure Switch, Black Light and Compact, Fits M1913/Pica tinny Rails and Weaver Rail pistol Slide Switch Activation or detachable remote pressure, Strobe/OFF/Constantly On, Windage & Elevation Adjustable Made with Glass-filled Nylon Composite, Only weight 1.6oz with battery(included) installed Dimension(inch):2 1/4 x 1 1/8 x 1 1/8 Operates with a CR2 battery(included)