Nite Life T-Shirts Men's Shutter Shades Equalizer Shirt 100% Cotton Shirt. Vibrant Panel - looks good on or off. High Quality Sewn on panel for clean look. 4-AAA battery pack for bright glow when illuminated (batteries not included). Durable black plug battery pack design. Pocket inside shirt to hold battery pack. Cloth sleeve over plug. Sound Activated LED Shirts