SYNC by 50 In-Ear Wireless Headphones, Sport Collection: Sporting Bluetooth wireless technology and patented ear hook design, the new Sport collection SYNC by 50 In-Ear Wireless headphones will stay put during physical activity and features water and sweat-proof protection - all while simultaneously giving users the ability to enjoy tunes without being tethered to a music device. Each pair features sweat-repelling nano technology, which protects against water immersion, safeguards against sweat, and withstands extreme weather. Included is a full-functioning MFI three-click Mic and a tangle-resistant cord that is reinforced for added durability. The SYNC by 50 Cent In-Ear Wireless headphones have professionally tuned micro drivers, and provide users high-fidelity audio, full bass response, and vocal clarity. Bio Sport uses an optical emitter to measure the smallest changes in blood flow through the capillaries. This results in the most accurate detection available for wearable monitors. Monitor every heartbeat, every time. Bio Sport is always ready to perform - mile after mile after mile. Bio Sport performs in any environment boasting an IPX4 rating for resistance to sweat & water. The 3-click MIC on the tangle-free cable is easy to use and sealed against the elements built-in optical sensor continuously measures accurate heart rate and removes noise signals caused by body motion. Bio Sport technology is built using an open architecture to optimize compatibility with the world's most popular fitness applications. Users don't need to change how they train to adopt this innovative technology because that's the way it should be.