When the light is poor, See'Ems™ turn bicycle wheels from "hard to spot" to "impossible to miss." Easy to attach and reposition and molded of tough, durable plastic, they're backed with stainless steel clips specially designed to snap securely onto oval, round, and bladed (flat) bicycle spokes. A bright, long-lasting LED is activated by a simple twist, and can be seen in even the darkest night to keep you seen and safe while riding your bike. Not only that - when the wheels are spinning, See'Em create the ultra-attention grabbing effect of a moving circle of light. Use one or several on each wheel to create your own signature bands of color.