Even the highest IPX-ratings are simply not enough to defend against the corrosive power of sweat. Spirit X implements a submarine-inspired structure and impermeable hydro-seal to create an impervious barrier around the sensitive internal components. When you are laser focused on grinding out the final rep or sprinting the last stretch, Spirit X sit almost unnoticed, fueling your effort with stunning sound. Ensure your tunes hold firm as you sprint, jump, and flip through your workout. No matter how close you go to your limit, Spirit X are guaranteed to stay in place.