Batteryguard prevents battery drain so you have power when you need it. Retains brightness up to 2x longer, 25% longer battery life. Allows batteries to be stored in headlamp for years. Fully adjustable head strap for comfortable wear. IPX4 water resistant design. Impact resistant up to 1 meter. Up to 200 lumens of light. Run time up to 6 hours on high and up to 200 hours on low. Beam distance up to 100M.