The moon crescent rear light is a 25 lumen usb rechargeable rear light that will always have your back the 15 chips high brightness red led gives off an eye catching glare that can bee seen for a long way away the light features 6 modes standard high over drive 50 flashing 100 flashing and strobe whether you are blasting home from work or getting up for an early ride you are able to choose a mode that perfectly fits the conditions and the battery life left in the light the only part