B007X72DVW Polar WearLink Nike Plus, Transmitter Set HR

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Provides heart rate information to nikeplus.com web service with compatible Nike+ devices, 5th generation and above iPods and the iPod nano
Uses coded 5 kHz transmission, ensuring that your Polar training computer finds your heart rate signal
Washable fabric strap
Water-resistant connector User replaceable battery
Kindly refer the user manual for troubleshooting steps