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Amazon.com : Polar T31 Coded Chest Transmitter and Elastic Strap - Black : Heart Rate Monitors : Sports & Outdoors
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Amazon.com: Polar Elastic Transmitter Strap Medium (34-55 Inch Chest) for T31 or T61 Transmitter : Sports & Outdoors
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Amazon.com : Polar T31 Coded Chest Transmitter and Elastic Strap - Black : Heart Rate Monitors : Sports & Outdoors
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