Polar H10 Black XS-S Brand New Includes Two Year Warranty Product # 92061852 XS-S Product # 92061851 M-XXL Already the gold standard upon which consistent and accurate heart rate technology recording in is based, the updated Polar H10 is now the most versatile by integrating ANT wireless technology.Whether used with your favorite fitness app, 3rd party wearable or piece equipment found at you local health club, the Polar H10 will help you get the most out of your training.The Polar H10 Heart Rate Sensor Black provides advanced heart rate monitoring and features an entirely new measuring algorithm. Polar H10 is the newest evolution of Polar heart rate sensors that are known as the industry standard for heart rate tracking. The key features are the built-in memory with Polar Beat and also have CR2025 replaceable battery. H10 Heart Rate Sensor Black Features H10 Heart Rate Sensor Bluetooth Low Energy 5 kHz Transmission Frequency Waterproof to 30 meters 400 hours of operation time on a user replaceable Battery Firmware updates that enhance the functionality Enhanced Compatibility Can be used with hundreds of different devices that receive heart rate via Bluetooth, ANT or the 5 kHz coded wireless transmission technology Built-in Memory Store 1 heart rate training session. Perfect for sports and activities where a wrist unit would be difficult to use