The easy-to-attach Nite Ize L.E.D. SpokeLit is the perfect way to increase your visibility, safety, and cool factor when youre riding your bike in the dark. Fueled by an efficient L.E.D bulb, this handy little device has two illumination modessteady glow and continuous flashto choose from. Press it onto the spokes of your wheel and slide towards the rim until the fit is tight, and it stays securely in place. And, heres the fun part: the SpokeLit not only marks your bike plainly in the dark, when youre riding at medium speed or faster, it creates the attention-getting effect of a moving circle of light. Water and shock resistant, it fits almost all kids and adults bike sizes.