Polar - Introducing Polar OH1 optical heart rate sensor. Optimized for use on the lower or upper arm, Polar OH1 provides an alternative method for measuring your heart rate during training. In
Polar introduces H10, its new 'medically accurate' heart rate sensor - Sports Finding
Amazon.com : Polar H9 Heart Rate Sensor – ANT + / Bluetooth - Waterproof HR Monitor with Soft Chest Strap for Gym, Cycling, Running, Outdoor Sports : Sports & Outdoors