Featuring a 3.0 MOA round aiming dot, the CTS-1550 will elevate your pistol's performance instantly. It utilizes the industry-standard J-Point or Shield RMSc mounting interface or "footprint" for easy installation on pistols designed to accept either of those optics. It incorporates an ambient light sensor that automatically adjusts to the lighting conditions and turns the device off when the included cover is used, extending battery life. The battery is located underneath the device to keep a lower profile and allowing co-witness in many instances. Designed for Compact and Sub-Compact firearms. Mfg: Crimson Trace Corporation