The Streamlight ProTac Rail Mount 1 is a 350 lumen weapon-mounted light featuring a dedicated fixed-mount for Picatinny rails. Multi-fuel innovation allows it to run on a single CR123A lithium battery or one easy-to-find AA alkaline/lithium battery. Features an integrated rail clamp that attaches securely to MIL-STD-1913 rails. Black Anodized Aluminum construction, ambidextrous, OAL 4.25, Body Diameter 1.20, Height 1.50, Weight 4.30 oz, Waterproof IPX7, modes Constant / Momentary / Strobe. Includes Remote Pressure Switch, Push-Button Tail Switch, and mounting hardware. Provides 1.75 hours of runtime on high and up to 14.5 hours on low using CR123A batteries.