The Streamlight ProTac Rail Mount 1 is a compact and powerful tactical light dedicated for long guns. Mounting to M1913 Picatinny rails with the integrated mount, the ProTac RM1 can be used with either a standard push button tail cap or an included remote switch giving the shooter out of the box flexibility. As an added bonus, it is a duel-fuel light, capable of running on Lithium or easy-to-find alkaline batteries (though at reduced output.).Features: Bright 12,000 candela beam reaches out to almost 240 yards Includes a multi-function tail cap and remote pressure switch Strobe feature (that can be disabled) Duel fuel system can be powered by (1) CR123A Lithium battery or (1) AA battery (lithium or alkaline) at reduced output IPX7 water proof to 1 meter for thirty minutes and impact tested to 2 meters with standard button switch IPX4 water resistant with remote pressure switch Durable aluminum body with anodized finish Compact size at just 4.25" and 4.30 - 4.50 oz Limited lifetime warranty through StreamlightModes: (CR123A Lithium) White LED High - 12,000 candela - 350 lumens - 1.75 hours runtime Low - 1,380 candela - 40 lumens - 14.5 hours runtime Strobe - 12,000 candela - 350 lumens - 1.75 hours runtimeModes: (AA Alkaline/Lithium) White LED High - 4,950 candela - 150 lumens - 4.5 hours runtime Low - 1,380 candela - 40 lumens - 14 hours runtime Strobe - 4,950 candela - 150 lumens - 4.5 hours runtimePrograms: High / Strobe (Factory Default) High only Low / High (Strobe disabled)Specifications: Battery Type: CR123A 3V Lithium or AA 1.5V Finish: Hardcoat Anodized Material: Aluminum Modes: Constant, Momentary, Strobe Output: 350 Lumens, 40 Lumens Platform: M1913 Picatinny Weight: 4.3 Oz