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.