Polar T31

Heart rate sensor. Slim, light and fully water resistant transmitter. Its purpose is simple: to transmit your heart rate to your wrist unit. Slim and light, the ECG (electrocardiogram) accurate transmitter is fully water resistant and designed for all weather conditions. Slightly different to the T31c Transmitter, the slim, light and waterproof T31 doesn’t have the benefit of coding for interference free transmission.