TLR-1 HL RAIL MOUNT TAC. LIGHT FLAT DARK EARTH 1,000 lumens; 1.5 hour run time; 20,000 candela; 283m beam distance Powered by two (2) 3-volt CR123A lithium batteries Rail grip clamp system securely attaches/detaches quickly and safely with no tools and without putting your hands in front of the muzzle Includes keys for GLOCK®-style rails, MIL-STD-1913 (Picatinny) rails, Beretta® 90two, Smith & Wesson® SW99, Smith & Wesson® TSW, and SIG SAUER® P320® rails