As the walkman, then discman, then iPod taught us, one of the best parts of any workout is being able to listen to your favorite pump-me-up tunes while you sweat. Unfortunately headphones aren't always up to the challenge of staying put and delivering consistent sound while being jostled in your sweaty ears. X-1's Momentum Ultra Light Headphones are earbuds designed with this in mind. With a selection of four ear-tips, these phones can be custom-fitted right out of the box. They are washable and won't short out after absorbing your sweat for weeks on end.