The LS-250G Lasersaddle(TM) is a feature-packed laser sighting solution for Mossberg 500, 590, & 590 Shockwave 12 Gauge Shotguns. Attaching seamlessly to the receiver, the LS-250G provides multiple ambidextrous laser activation pad points for instant targeting with a powerful 5mW green laser. As with all Crimson Trace laser sights, the LS-250G is user-adjustable for windage and elevation. The LS-250G features a Master On/Off Switch for completely powering down the system. This model provides 3 Hours of battery life with 4 provided CR2016 batteries. Fits Mossberg 500, 590 & 590 Shockwave in 12 Gauge only. Models must have receiver that is drilled and tapped. Does not fit 20 Gauge or. Factory sighted at 50Ft. 5 inch diameter at 50 feet.