The Silva Runner is an extremely lightweight & compact headlamp with great light output for the advanced runner or skier. The lamp unit is in aluminum for optimal cooling. Two high power LEDs provide you with Silva Intelligent Light light where you need it. An external rechargeable battery pack that can be attached to the extra wide headband or to a belt or placed in the pocket of your running jacket or rucksack, ensures you have enough power for your evening or early morning exercise. Runner has a large on/off button that is easy to operate even when wearing gloves. Specifications; Battery life 10 hours Lumen count 550 Battery type 2, 5 Ah 7, 4V Li-ion Weight (excl batteries)62g Light distance 90m