Rear bike light with two high-bright LEDs and USB charging directly via the built-in connector. Easily attached with a rubber strap to your saddlebag, Topeak panniers or bike helmet. You'll be able to see up to 2 km with this light. Charged to be seen! The TailLux 25 USB design features convenient cable-free charging with a direct USB port plug. Two super bright LEDs provide 25 lumens and three light modes, so you can be seen up to 2km away - even on the darkest nights. Bi-directional tool-free mounting and removal is accomplished by a single silicone strap making it simple to use on seatposts, seatstays or Topeak bags. (with included bag clip) Maximum luminous flux: 25 Lumen Light source: 2 super bright red LED's Battery: 3.7V 320mAh Lithium Ion (integrated) Lighting modes: 3 hr (High) / 30 hr (Low) / 40 hr (Blinking) Charging: USB port / 2 hrs. Input: 5V 500mA Light material: engineering grade polymer Fixing: rubber belt, on seatpost (ø25.4 - ø34.9mm), Topeak panniers, cycling helmet Waterproof: IPX 6 Dimensions: 6.3 x 2.7 x 2.5 cm Weight: 30 g