This Soft Transmitter Strap is the most comfortable chest strap for heart rate measurement. The Soft fabric and adaptive electrodes are extremely sensitive to your heart’s electrical signals making it easy for the sensor to read your heart rate quickly and accurately. This Heart Rate monitor chest strap replacement is compatible with the following heart rate monitors: Wahoo Blue HR Wahoo Tickr Polar Loop Polar Wearlink Polar Nike + Polar Polar H7 Polar WIND Polar Bluetooth Polar H1 Polar H2 Polar H3