Pounding bass: 12 mm Composite drivers transform your music into a workout-fueling, bass-driven soundtrack. Sweat proof: Push your workout to the limit with zero hesitation thanks to IPX7 water resistance and Sweat Guard technology. Engineered for comfort: secure-fit, ergonomic design, and controlled entirely from the right earbud; zero rubbing or pulling from an in-line remote. Huge Stamina: get 10 hours of playtime. That?s over a week of gym sessions from a single charge. Hands-free calls: built-in microphone for clear call quality