TechnoTeez sound activated equalizer light-up animated LED shirts use electro-luminescence and IC chip technology to create a radiant pulsating display to the beat of music! A small power pack driver sits comfortably in a hidden pocket located inside the TechnoTeez shirt which controls the flashing and blinking (requires 4 AAA batteries). Absolutely the most amazing thing to make anyone stand out in a crowd. Each TechnoTeez set comes complete with a design panel, a driver unit, and a t-shirt. Most TechnoTeez design panels are approximately 2.5"-3.5" wide depending on design. Drivers can be set to multiple selectable patterns! This is a light-up graphic equalizer that is sewn right onto the TechnoTeez shirt and actually will bounce up and down to music or other sound sources. The super-thin flexible TechnoTeez design feels somewhat like a thick iron-on transfer. Comes with a tiny driver unit that sits in a hidden pocket on the inside of the shirt. Select either high or low sensitivity to sound. High sensitivity is great to watch the t-shirt respond to voices or everyday sounds. Low sensitivity is used in clubs where there is high-volume music blasting. The gradient equalizer design is one of our large TechnoTeez designs and measures about 5.5" x 4.25". All TechnoTeez t-shirts are 100% cotton and hand-washable/hang dry (do not launder in machines). Simply remove the driver unit and cables from the inside of the shirt. All TechnoTeez T-Shirts come in size LARGE and color black, to make the effect more dramatic while wearing it in the dark. Your T-Shirt is ready to use right out of the box and includes 4 "AA" batteries already installed!