NiteRider Pro 3600 LED Light Bulb Type: Cree LEDPower Source: Li-Ion battery packBackup Power Source: yesBattery Location: external packBatteries Included: yesVoltage Regulator: noModes: DIY mode adjustmentBulbs: sixLumens: 3600Burn Time: 1.5 - 36 hoursWaterproof: no, water-resistantWeight: 812 gRecommended Use: dark trail ridingManufacturer Warranty: 2 years