INTON Aircraft aluminum Waterproof rechargeble USB Bike Light with USB charger 300 lumens Headlight size: Dia29*63mm, Easy to carry Use the Cree led XLamp XPG- R5 of the famous US Cree led company, 300 lumens 3.7V 900mA/h 118350 li-ion battery, its not necessary to worry about there is no power of Bicycle Light Waterproof bicycle light can correspond to the all-weather with the waterproof O-ring The Headlights guarantee time is one year