The Defender Series provides a seamless trigger guard or grip replacement fit with cutting edge design, superior technology, and an affordable price tag. It features Beam Lock Adjustments so the user can easily adjust for windage and elevation, and the unit is pre-sighted at the factory at 50 ft. The Dual Side N-Gage Activation Buttons provide an easy-to-find, bright red activation button with auto shut off at 3 minutes. Defender Series emits a powerful (5mW peak, 620-670nm, Class 3R) red aiming laser. This model is compatible with Glock Gen3 17, 17L, 19, 20, 20SF, 21, 21SF, 22, 23, 31, 32, 34, 35, 37, 38, Gen4 17, 19, 20, 21, 22, 23, 34, 35, and Gen5 17, 19, 19X, 45.