Requires at least 1 3/4" of rail space Rail Mount Laser Made in USA Highest visibility in ALL lighting conditions. Incredibly lightweight - weighs ONLY 1oz. with batteries Integral Picatinny rail system to allow a wide variety of accessories to be stacked right onto the green laser system. Ambidextrous activation to accomodate the left or right-handed shooter. Constructed from FRN (Fiber Reinforced Nylon) for lasting durability. Maintains alignment after every battery change.; Class IIIa Laser Product: &lt;5mW power output Class IIIA laser, &lt;5mW power output