Cygolite Rover II LED: Dual LED Bike Light with Frame Mount NiMH Battery Dual LED bike light with 3rd-generation, high-brightness LED bulbs LED output equivalent of 25-watt halogen light (255 lumens) 4 brightness modes (high, low, boost, and flash) Ultra-compact NiMH battery runs for 3.5 hours on high setting Charges in 6 hours; weighs 0.85 pounds combined (head and battery)