Never before has a wearable computer been so, well, wearable. Hexoskin is a workout tank top that looks like something you’d pick up at Nike, except for all those sensors in the lining. The shirt measures heart rate, calorie burn, step count, and breathing, all while showing what your body is up to on your iOS or Android app. When you inhale and exhale in real life, the lungs on your body’s outline in the app glow blue and retract and expand along with you. It’s incredible to watch, but also incredibly expensive: One shirt, along with the little Bluetooth device you need to wear in your pocket to record your activity, retails for $399. (Although you can wash the shirt in cold water, so no need to buy multiples.) Hexoskin will also work with Android smartwatches released this year, the company announced at CE Week.