... a visual rhythm guide to others. It is powered by a battery pack that put within inside of ... Made from 100% cotton, this high tech.6. Powered by a battery pack cleverly hidden within an inside shirt ... AAA batteries (batteries not included), or DC 6V power supply Size: M,L,XL,XXLNet weight: 254gPackage ... . Remove EL panel,battery pack and the whole power cord carefully before washing3. Do Not submerge any ...