This Polar H7 heart rate sensor strap is a great way to track your heart rate during exercise. It is a purple and black strap designed for both chest and upper arm wear and can be used with a variety of compatible devices. It includes a durable chest strap and transmitter unit for accurate and reliable readings. The strap is lightweight and comfortable to wear, with an adjustable size for a secure fit. A practical must-have for any health and fitness enthusiast.