The F500 from ETC is a 500-lumen front bicycle light that features a lithium battery allowing USB recharging, and equipped with four lighting modes. Never be without light - The light sports a lithium battery which saves the need of carrying spare batteries, you can simply USB charge the light before each journey whether at home, at work on-the-move during the day with one of our Goal Zero's portable power banks. Overview: Light source: 6 watt white LED head light Luminous Flux: 500 lumens 100%-70%-50%-25% steady-flash-off with low battery indicator Battery: 18650 Lithium battery 2000mAh USB rechargeable Waterproof: IP44 Bracket size: 22.2-31.8mm Product Size: 105.2 x 35.5 x 37mm Fitment: Clamp