These powerful, intensely bright, long-running, aluminum-bodied gun mount lights set a whole standard for durability. They're shockproof, dust-proof, waterproof, and virtually destructible. The 3-watt Luxeon led won't break or burn out. The rail grip-clamp system securely attaches/detaches quickly and easily with no tools and without putting your hands in front of the muzzle. They fit most handguns with rails as well as long guns with 1913 (Picatinny style) rails. The TLR tactical lights give you every advantage in any low-light situation.,