Nitecore HC30 1000 Lumen Headlamp Direct access to turbo mode Integrated Precision Digital Optics Technology provides extreme reflector performance Featuring Advanced Temperature Regulation (ATR) technology to dynamically adjust output performance based on its internal temperature Special head switch for quick operation with one hand Reverse polarity protection prevents damage from incorrectly inserted batteries Toughened ultra-clear mineral glass with anti-reflective coating Constructed from aerospace grade aluminum alloy Robust HAIII military grade hard-anodized Comfortable chafe-free and breathable nylon headband Waterproof in accordance with IPX-8 (two-meter submersible) Impact resistant to 1.5 meters Tail-stand capability Length: 3.86 (98.0mm) Head diameter: 0.95 (24.2mm) Tube diameter: 0.94 (23.8mm) Weight: 1.42oz (40.3g, without battery)