T31c Coded Transmitter Set

At the heart of your training is the coded T31. 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
Built to last with up to 2500 hours of training usage Prevents cross-talk from other electrical devices for accurate measurement of your training No user replaceable battery