CardioSport Go 15S Heart Rate Monitor Watch with Stretch Fabric Transmitter ECG accurate heart rate with hi/lo training zone in signal beat increments Scan of maximum, average & minimum heart rate for workout. Memory recall of last exercise session. Stretch fabric transmitter. Machine washable with user changeable battery Water resistant to 30 meters. Automatic switches off when chest transmitter is removed Electroluminescent light Stretch fabric transmitter