NightRider Lumina Micro 220 Head Light Internal Lithium Polymer battery charges in only 3 hours via USB cable Built-in indicator light switches from red to blue when the battery is fully charged High-powered Cree LED produces more light with less power and less heat Custom made reflector and Borofloat lens work together to minimize light transmission loss and maximize light output for excellent optical clarity -- superseding internal reflectors or standard glass lenses Runtimes: 1 hours High (220 lumens), 2 hours Medium (120 lumens), 4 hours Low (80 lumens), 14 hours Walk (15 lumens)