iHeartRaves Unicorn Sound Activated Light Up Rave Shirt (Medium) QUICKLY Music festivals Raves Concerts Parties Holiday Events Costumes Trade shows &amp; corporate events ...Or any night time event! Adjust the flashing speed with the volume sensor Powered by 4 AAA batteries Lasts 10-14 hours (depending on the length of use &amp; battery brand) Unplug the battery pack for easy washing