The Topeak 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)