Under Armour39 Chest Strap
TECH SPECS 
SizeOne Size Fits All
ChargingNo
BatteryCoin cell battery
Battery life
Water resistanceSweatproof
Weight
SensorHeart rate sensor
ConnectivityBluetooth
Internal storage120 days
METRICS 
Heart rateYes
Heart rate variabilityYes
Running metricsNo
Swim statisticsNo
OtherStores biometric info—including heart rate, calories burned, real-time intensity, and WILLpower™—and transmits it automatically in real time to the MapMyFitness apps, Armour39 app, or Watch
LINKS 
Affiliate link*Amazon
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