Changing battery to Polar H7 heart rate sensor - YouTube
Polar H9 Heart Rate Sensor – ANT + / Bluetooth - Waterproof HR Monitor with Soft Chest Strap for Gym, Cycling, Running, Outdoor Sports: Buy Online at Best Price in UAE - Amazon.ae
Polar H10 Heart Rate Monitor – ANT +, Bluetooth - Waterproof HR Sensor with Chest Strap - Built-in memory, Software updates - Works with Fitness apps, Cycling computers, Sports and Smart watches: