This little light is awesome. I can always depend on it to turn on and stay on, which has been a problem with other pricier tail lights that I have used. And it seems to be just as effective alerting cars to my presence as any other tail light I have used. But more importantly, it is small and discrete keeping your bike looking sleek while cruising to, from, and around campus (rather than a big goofy red light dangling off your seat post). To install you simply pop out the Fi'zi:k logo under your saddle and clip the light in.