An activity tracker is a useful tool for you to keep track of your workout. It weighs 31 g. Use the built-in heart rate monitor to keep track of your training progress.
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Garmin 010-01955-50 Vivosmart HR Plus - S EU, Blue, Regular
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Unisex Garmin Vivosmart HR+ Alarm Chronograph Watch - Black / Black
Garmin
vívosmart® HR+