The NiteRider FireStorm HID Bike Light System is a member of NiteRider's Class IV HID lights. Powered by a 4.0AH NiMH battery pack, the FireStorm will burn at full brightness for up to 4 hours on a charge. Its NR 2.5 International Charger allows you to recharge your battery to full capacity in 2.5 hours or less. Equipped with new fast-start electronics and a bulb-saving safe-shutdown sequence, the NiteRider FireStorm HID Bike Light System also tells you when your battery is getting low and you're on reserve. Smaller and lighter than its predecessors, but still NiteRider tough, this is quality at its best!