LED Flexible Light Strips may be worn as a headband, wristband, necklace, or anklet, and can be used for costumes, decoration, and whatever else your imagination can dream up. Wrap LED Flexible Light Strips once around your head or neck, 3 times around your wrist, or twice around your ankle – then easily attach the two ends via the velcro fastener. The length/circumference is adjustable from 16″ to 24″, so they fit almost anyone. Also, LED Flexible Light Strips can be cut permanently shorter, if so desired. LED Color: Blue LED strip length: 22″ (33 LED’s) Strip background: Black Fastener: Velcro Battery: 23A alkaline, 12V (included, replaceable) Battery lifetime is typically 5-10 hours. The battery will recover somewhat with rest, so it may last longer if used for shorter periods, rather than +5 hours at a time. The battery is easily replaceable; just slide the battery sleeve down, replace the battery, and slide the sleeve back up. While LED Flexible Light Strips are water-resistant, completely submerging them for extended periods of time is not recommended.