Glock owners: If you have a Glock with the MOS system optics cut, this is the dot for you. The TSR1-M is designed to eliminate any mounting issues on Glocks utilizing the MOS system. With 50,000 hours of battery life and motion sensor activation, the TSR series is always ready. The low profile, allows this sight to co-witness with appropriate suppressor height iron sights on Glock MOS slide-cut pistols. Features FULLY MULTI-COATED Effectively reduces reflected light and increases the transmission of light giving you a brighter image than normal single coated lenses. MOTION SENSOR Built in motion detector automatically wakes the product up from the sleep mode when a motion is detected. EXTENDED BATTERY LIFE Offers 50,000 hours battery life at medium illumination setting.