The ProTac Rail Mount HL-X is a 1000 lumen weapon-mounted light featuring a dedicated fixed-mount for Picatinny rails. It uses either a remote switch with momentary/constant on operation or a standard push-button tail switch and runs on either two CR123A lithium batteries or one Streamlight rechargeable 18650 battery Features TEN-TAP? Programming ? Choose from three user selectable programs: 1.) high/strobe/low; 2.) high only; 3.) low/high C4? LED illumination output and run times: High for maximum illumination; Low for extended run time; Strobe for signaling or disorienting Fixed rail grabber with thumbscrew easily attaches to Picatinny rails (no tools required) Solid State power regulation provides maximum light output throughout battery life Dual fuel - uses two CR123A lithium batteries (included); also accepts one Streamlight rechargeable 18650 lithium ion battery Remote pressure switch features momentary and ?constant on? operation Remote pressure switch features momentary and ?constant on? operation Integrated rail clamp attaches to MIL-STD-1913 rails Easy to attach secure mounting Durable anodized aluminum construction with impact-resistant tempered glass lens IPX7 rated with the Standard button switch installed; waterproof to 1 meter for 30 minutes. IPX4 rated with the Remote Pressure Switch installed Operating temperature: -40?F to +120?F Durable anodized aluminum construction Anti-roll head Includes two CR123A lithium batteries remote pressure switch push-button tail switch remote retaining clips double-sided tape and zip ties RoHS compliant Limited lifetime warranty