The comet rear features a 1 piece cob led that generates 30 lumens of light this innovative light delivers a type of light that is really visible the rear light comes as standard with seat post and saddle rail bracket technical details 1 pce cob high brightness led 30 lumen output internal li ion battery usb rechargeable 2 hour usb charge time full beam 3 hours low beam 7 hours features usb rechargeable flashing constant modes low battery indicator auto charge cut off side visibility includ