360 DEGREE PIVOTING - Rotate the light to any direction with its articulating arm ALL NIGHT COVERAGE - The HM01 accepts a single CR123A or RCR123 battery and can operate up to three hours on the high setting and 15 hours on the low setting. HANDS FREE - An ideal secondary fill light for ballistics helmet users, the HM01 provides stable near-field visibility while frees the primary light for tactical operations. ARC RAIL HELMET LIGHT - The Nitecore HM01 is capable of a 320 lumen well diffused flood beam thanks to its TIR optic lens, an ideal secondary fill light for tactical helmet users for near-field vision