Trijicon RMR 6.5 MOA Adjustable LED Red Dot Sight 6.5 MOA LED WITH ADJUSTABLE BRIGHTNESS: Features an automatic brightness mode and controls for eight adjustable settings including 2 NV and 1 super bright EASY PUSH BUTTONS: The brightness adjustment buttons are designed to be easily manipulated and accessible UNIQUE PATENTED HOUSING SHAPE: Forged 7075-T6 aircraft aluminum-alloy housing shape diverts the force of an impact away from the lens, greatly increasing the durability of the sight TRUE-COLOR MULTI-COATED LENS: Creates a wide-band light transmission for minimal change in target area color ADJUSTABLE WINDAGE / ELEVATION: Easily adjustable without special tools. 1 MOA per click; Kindly refer the user manual attached below for troubleshooting steps and instructions Compatible on a variety of Handguns like Glock MOS, Springfield Armory OSP, Smith & Wesson CORE, FNH Tactical, etc.