Polar T31 coded transmitter - Slimline & contoured. Positioned on the chest, it measures heart rate per minute in real time. As Polar Transmitters are ECG accurate and 100% waterproof, they are the most effective exercise tools for measuring your heart rate.Features: For use with the M series and S series (Excluding S120 & S150) Fully water proof, light weight and extended battery life come with a 2 year Polar warranty covering Tranmitter electronics, electrodes and battery
