Serfas' TLM-1 Magnetic LED Taillight is pure genius. This little life-saver boasts 2 red ultra-bright LEDs with a reflective body for maximum visibility. But that's not the best part. It also magnetically attaches your your shirt, pack or whatever so it's perfect for walkers, runners, riders, everyone. It has steady, strobe and flash modes with up to 100 hours of run time from the included lithium battery, too.