IPX4 WATER RESISTANT - Highly airtight construction - strong and waterproof. These bike tail lights are water resistant for any weather, and extremely durable. USB RECHARGEABLE - This bicycle tail light can be charged by USB cable via computers, chargers or portable power banks. This will save you lots of money on batteries. Battery life is great! EASY TO USE - Hook onto your belt, running gear, reflective vest, backpack, dog collar, harness, or anywhere on your clothing. Mount to your bicycle, helmet, skateboard, scooter, stroller, wheelchair, or anywhere you can imagine. DAYTIME VISIBLE TECHNOLOGY - Did you know that 75 percent of cycling accidents happen in daytime? This red bike tail light keeps you visible not only at night but also in the daytime, keeping you and your loved ones safe all the time. ULTRA BRIGHT TO KEEP YOU SAFE - This rear bike light 240 degree wide angle visual design provides more visibility than any light on the market. Whether you're running, walking with your dog, cycling, skateboarding or hiking, these safety back bike lights for night riding will keep you safe and secure.