CREE XM-L LED, with a lifetime of up to 50,000 hours; Tactical Tail cap press button switch, slightly depress the side switch for different output modes and standby mode: Three modes constant output, hidden strobe, SOS (below is the output and runtime of using two 2600mAh 18650 batteries)Three constant output modes: 845Lumens (2hrs)- 220Lumens (8hrs)- 20Lumens (60hrs)Strobe: 845 Lumens: 845 Lumens Constant current circuit, constant output Effective range of 500 meters Uses two 18650 or four CR123A batteries Working voltage: 5.5-16.8VHigh quality reflector maintains great throw distance and spread with an ideal beam pattern Dimensions: 225mm (length) x 64mm (head diameter) x 25.4mm (tail diameter)Weight: 273g (battery excluded) Aerospace-grade aluminum alloy Military Specification Type III- hard anodized body Waterproof, in accordance with IPX-8 standard Ultra-clear tempered glass lens resists scratches and impacts Tactical forward click switch with momentary on Accessories: tactical ring, holster, O-ring, rubber cap.