Rear light with one red high power 1W LED with one function. Thanks to the universal bracket with tool-free assembly can be adjusted vertically direction too. Visibility of light is in 240° angle. Li-Polymer Battery (3. 7V 240mAh) rechargeable through USB port using the supplied USB cable. Charging time 2-3H approx. Charging status indicator informs you when the battery is fully charged. Light also has a built-in low battery indicator. Weight 27 grams.