What do you wear when your T-Equalizer shirt is dirty? The latest in geekwear, the sound sensitive 4D Equalizer Tee which keeps the beat to the music, even if you can’t. Like most shirts of this type, the battery pack fits into a pocket and is removable for washing out the remnants of the night before. Made from cotton and available in four sizes, the t-shirt runs on 4 AAA batteries (not included) and will be in stock February 29 for £24.99 (~$49.00.)