The Streamlight TLR-1S is powered by two 3-volt CR123A lithium batteries with a 10-year storage life and comes equipped with C4® LED technology, making it impervious to shock with a 50,000 hour lifetime and a rating of having a 12,000 candela peak beam intensity and up to 300 lumens measured system output. Deep-dish parabolic reflector produces a concentrated beam with optimum peripheral illumination. Capable of running up to 2.5 hours, it has solid-state current regulation for consistent illumination level. The rail grip clamp system securely attaches/detaches quickly and safely with no tools and without having to put your hands in front of the muzzle. It mounts directly to handguns with Glock-style rails and to all MIL-STD-1913 (Picatinny) rails and includes keys for Glock-style, Picatinny, Beretta 90two, S&W 99 and S&W TSW. It has an ambidextrous momentary/steady on-off switch, and a double tap of the momentary paddle within 0.4 seconds activates strobe.