WARNING AT NIGHTThe led armband is designed with high visibility led lights and reflective materials,provides greater visibility than other reflective sports equipment,make your activities at night safer.ADJUSTABLE VELCRO SIZEReflective running gear have adjustable Velcro can be flexibly used in various sizes, and you can wear it on your wrists, ankles, arms and backpacks.Strong men, children, elderly, women and other people of all ages can easily wear it.Rechargeable ArmbandUSB charging is more environmentally friendly than batteries, and it can also save you money on batteries,batteries' storage capacity goes to 3-4 hours,one charge lasts a week.WIDELY APPLICABLEThe led armband for walking,cycling,dog walking, mountaineering, running, camping and all outdoor ,used for rain, fog, dark,cloudy,night and other low visibility conditions.Three Lighting ModeRunning light armband has three lighting modes: fast flashing/slow flashing/continuous light,the weight is only 25G. It is very light and easy to carry.