Crimson Trace Lasergrips provide a pinpoint accurate laser each time you naturally grip the firearm, no fumbling for switches or buttons. Installation can be done in a matter of minutes and only requires the removal of the trigger group pin and your laser grip will snap right over the back strap of your Glock. Front activation switch activates instantaneously due to pressure applied to the switch located forward of the grip surface. Lasergrips produce a 1/2" dot at 50 feet and are a class IIIa Diode Laser (Non-hazardous to eyes under momentary exposure). The included batteries have a five year shelf life and have a four hour in use life. Crimson Trace also extends one free set of batteries a year for life when you register you Crimson Trace product on the manufacturers website. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.