The DS-124 Defender Series Accu-Grips Laser Sight by Crimson Trace fits Smith & Wesson J-Frame (Round Butt) and Taurus Small Frame Revolvers. The Defender Series sets a new standard in laser sighting systems by providing cutting edge design, superior technology, and an affordable price tag. The DS-124 features Beam Lock Adjustments so that the user can easily adjust laser sighting for both windage and elevation, and the unit is pre-sighted at the factory at 50 ft. The Top N-Gage Activation Button provide a large, easy-to-find, bright red activation button, which emits a powerful (5mW peak, 620-670nm, Class 3R) red aiming laser. Fits: Smith & Wesson Airlight, Airweight, Bodyguard, Chief’s Special, Centennial, Ladysmith, Models 36, 37, 38, 49, 60, 63, 317, 331, 332, 337, 340, 342, 351, 360, 442, 637, 638, 640, 642, 649, 651 and 940 – Round butt only and Taurus Small Frame Revolvers (85, 94, 605, 650, 651, 731, 850, 851, 856, 905, 941). This laser is in conformance with and complies with 21 CFR 1040.10 with a maximum power output of “5mW” for a “Class IIIA” laser.