SMS Audio SMS-EBBT-SPRT-ORG SYNC by 50 In-Ear Bluetooth Sport, Orange BioSport 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. There are no bulky battery packs to add weight no charging required. BioSport is always ready to perform - mile after mile after mile BioSport 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 BioSport technology is built using an open architecture to optimize compatibility with the worlds most popular fitness applications. Users dont need to change how they train to adopt this innovative technology - because thats the way it should be