Nightstick FORGE Helmet-Mounted Multi-Function FlashlightFORGE Helmet Mounted Multi Function Flashlight The NSP 4640B Helmet Mounted Multi Function Flashlight is the most versatile choice for helmet mounted hands free lighting. The 4640 outshines the competition with its powerful 360 lumen tightly focused flashlight and a beam distance rating of 218 meters (715 feet). The user can also choose a lower 180 lumen setting for increased runtime. The 4640 also features a 30 lumen for 30 hours Survival Mode. The