A quick and easy elastic band secures the TraceR Rear Light to seatposts like many other LED safety lights, but Exposure's expertise makes this much more than a watch battery in a rubber case. First off, the TraceR Light combines a powerful, yet efficient Cree XPG LED with a lightweight 700 mAh Lithium Ion battery in a CNC'd aluminum body. When compared to a plastic body, it's much more durable and efficiently transfers heat from the LED, ensuring an extremely long bulb and battery life. In flash, low, a Trace will last 24hours, and in high, steady, the light will give you 75 lumens of light for three hours. The Trace features Exposures Optimum Mode Selector with three brightness modes and the choice of solid or pulsing beams and use a USB interface to charge Exposures' Trace light also uses a fuel gauge with a traffic light system to make it clear when it's time to recharge.