Adjustable SizeThe LED sports armband has a dimension of 1x 13.78, simply adjust the night train to the right length and button it to use. It is lightweight and comfortable for adults and children or pet.High visibility and safety at night: The light strip is designed to give you 360 degree ultra-high visibility in the dark, which has higher brightness than light sticks, ensuring greater safety for you, your children or pets at night from reckless and distracted drivers. This LED armband is perfect for running, jogging, cycling and other outdoor sports.Water and sweat resistant: This LED light bracelet is made of nylon fabric and materials Special waterproof LEDs that protect your cuff from water or sweat, so there is no need to worry about electrical leaks and short circuits, ensuring greater safety./ LED running armbands and glow bracelets are designed for people who like to run in the morning or evening, jogging, cycling Wider adjustment range with elastic bands, one size. Highly visible Light mode: constant glow, flashing, off. The mode can be changed simply by clicking the switch button Available color: blue, red, pink, green, yellow, orange, white. Size: 1x 14.2 inches Possible applications: Children;have fun in the evening Glow Party Runners or joggers People walking their pets Cyclists. They can attach the LED bracelet to any part of the bike Campers Package included: 2PCS Armbands. Note: The data are all manually measured, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual item received shall prevail.