iHeartRaves EmazingLights DJ Sound Activated Light Up Rave Shirt Black cotton t-shirt with a sound activated illuminating panel Adjustable volume sensor for the flashing speed The lights flashes colors in time to music and sound On/off battery switch Easy battery removal for washing 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