The Streamlight TLR-1 is a virtually indestructible, rail-mounted tactical light designed to attach to almost any firearm in seconds. It features a 300-lumen C4 LED focused by a Borofloat glass lens, providing a powerful beam for at least 2.5 hours. Constructed from lightweight black anodized aluminum, the 4.18-ounce unit is waterproof and utilizes a specialized rail clamp system for rapid attachment and detachment from the side of the weapon. It features ambidextrous tail cap switching for momentary or constant activation and includes a tethered battery door to prevent loss during replacement. Powered by two CR123A batteries, this 3.39-inch light is an industry standard for professional reliability on both pistols and long guns.