Suunto Smart Heart Rate Belt 2 brings precision to serious training — accurate heart rate and high-resolution R-R data for athletes training by intensity. ECG-based detection filters out artifacts, while a redesigned chest strap resists interference, keeping your trace steady through intervals and long efforts – exactly the data quality ZoneSense needs on a compatible Suunto watch. About 460 hours of battery life keeps maintenance rare. On a compatible watch, a six-axis sensor adds running-form data – cadence, ground contact time, vertical oscillation, flight time, and left/right balance – with 20 hours of onboard memory to bridge signal drops. It also connects to three devices at once, sending the same live heart rate to a watch, bike computer, and phone if needed. Learn more at suunto.com #AdventureStartsHere