Be seen with this rear light from M-Wave. The light provides enough light to be visible in low light conditions. Having light of your own can make you more visible, and therefore safer, than relying on reflectors. The light can mount to almost any seatpost with a diameter of . 75 - 1. 4 inches (19 - 35 mm). The 240 degree illumination angle makes sure you are as visible as possible. It operates with one red LED bulb powered by a battery you can recharge with an included USB cable. The light is also equipped with a battery level indicator so you never have to guess on the light's battery life.