Crimson Trace Red Lasergrips for Smith & Wesson N-Frame, Round Butt - LG-314 This laser is in conformance with and complies with 21 CFR 1040.10 with a maximum power output of "5mW" for a "Class 3R Red Laser Beam intensity: 5Mw peak, 633nm, class IIIA laser. Maximum output that federal Law and technology allow Fits Smith & Wesson models 20 thru 29, 57, 58, 325, 327, 329, 520, 610, 624, 625, 627, 629 and 657. Finish - Rubber Overmold Grip, Attachment - Grip Replacement, Activation Location - Front Activation Battery Type - Two #2032 Batteries (Included)