Knog Plus Twinpack is a set of Knog Plus front and rear flashers. Knog Plus is a very bright, 100% waterproof and versatile USB rechargeable light. Clip it under your saddle, on your seat post, or use the integrated clip to attach it to your jersey pocket, backpack strap, or bike bag.Are you more of a runner than a cyclist? No problem. The Light Plus is usable for nighttime illumination. Just tuck it behind your shirt, shorts, socks or headband with the smart integrated clip and the flashlight will ensure all athletes are highly visible throughout the day and night. Weight: 12 g Luminosity: 40 lm front / 20 lm rear Battery life: 2/40 hrs 5 USB modes Magnetic clamp