Blackburn System X6 Bicycle Lights Two heads with Luxeon III emitters, one wide beam and one spot beam 85 lumens of pure white light makes each head equivalent to a 12-15W halogen Constant Current technology maintains near-full brightness throughout runtime 30, 70, and 100 percent dimmer switch allows 3.5 to 14 hours of run time Lightweight five-cell NiMH battery with Supercharger achieves full charge in 4.5 hours