NEW in unopened box. Includes heart monitor, small arm band, large arm band, and USB charger. Scosche Rhythm+ heart rate monitor band works with most popular health and fitness apps. This heart monitor employs patented optical sensor technology for highly accurate monitoring and measurement. The high-quality Scosche Rhythm+ Armband excels in providing remarkably accurate measurement of exercise intensity. "Breathable" neoprene armband design means greater comfort and ease of use. Comes with both a large and small armband. This fitness tracking array provides superior measurement across all skin tones, making the Scosche Rhythm+ Armband superior to monitors and watches that employ only green sensors. With IP67 sweatproof and waterproof construction, you can count on this wearable fitness tracker's exceptionally accurate performance in both wet and dry conditions. The award-winning Scosche Rhythm+ Armband Heart Rate Monitor can even be submerged up to one meter, which is why this comfortable, wearable device is perfect in wet or dry environments.