Requires at least 3/4" of rail space Fits more firearm models than any other laser Ideally suited for the smallest compact and subcompact pistols Automatic time-out after 10 minutes prevents inadvertent battery drain Distinct ambidextrous TAP ON/TAP OFF switch reinforces safe firearm handling Convenient Quick-Change Battery Hatch permits safe on-the-gun battery changes; Class IIIa Laser Product: &lt;5mW power output Class IIIA laser, &lt;5mW power output