Whether for commuting or weekend riding, the NiteRider Lumina Micro 850 Front Bike Light will keep you visible and thereby safe.Low battery indicator changes the power button from blue to red when there is approximately 15-20% battery life remaining.Lock mode prevents activation during storage and transportation; simply press and hold power button for 7 sec..Weight: 4.6 oz..Charge Time: 1.75 hours.High: 1.5 hours.Low: 9 hours.Flashing: 10 hours.