The exposure flare rear light is a super bright tiny rear light powered by a removable cr123 battery simply clip it onto your seat post for 75 lumens of red light just twist the head to turn on and off and switch between solid and pulsing modes the flare can also be mounted under the saddle using the saddle rail bracket the flare can be bought alone with a disposable battery or with the flash front light and a usb charger in the flash flare pack exposure flare rear light features