Product Features: Uses 4 CREE XP-G3 S3 LEDs, maximum luminous flux of 2,700 lumens Lightweight and robust CNC machined body for superior cooling performance Beading optical lens provides uniform and soft light source Maximum illumination capacity 4,500cd, maximum illumination distance of 134m 21700 lithium ion battery for continuous use 1200 hours It can also be used with 18650 lithium-ion rechargeable batteries or CR123 batteries. 5 brightness levels and 3 special modes with 1 switch. Built-in charging function allows you to charge the lithium-ion battery via micro USB. NITECORE 21700 lithium ion rechargeable battery included (NL2140HP 4,000mAh). Flash speed in strobe mode is randomly changed to increase the effectiveness. Power indicator under the switch notifies the remaining battery level (Patent No. ZL2012012012012012 00577 67.4) Power indicator notifies battery voltage (±0.1V); Built in high performance temperature control (ATR) (Patent No. ZL201510534543.6); Specially designed lightweight and breathable headband with anti-reverse function made of aerospace aluminum alloy HA III hard anodized aluminum alloy Treated waterproof Dustproof IP68 (2m Submersion) Shockproof 1m Freestanding Magnetic Tail Cap