Crimson Trace Corporation, Defender Series, Accu-Guard Laser, For Glock Full-Size and Compact, Black Finish WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov. Switch activation Red laser Factory sighted at 50Ft .5 inch diameter at 50 feet The DS-121 Defender Series(TM) Accu-Guard(TM) Laser Sight by Crimson Trace fits GLOCK Full-Size and Compact pistols. The Defender Series sets a new standard in laser sight for GLOCK pistols by providing cutting edge design, superior technology, and an affordable price tag. The DS-121 features Beam Lock(TM) 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 Dual Side N-Gage(TM) Activation Buttons provide a large, easy-to-find, bright red activation button, which emits a powerful (5mW peak, 620-670nm, Class 3R) red aiming laser.