Devices that track heart rate and other vital signs in real-time, often used for fitness and health monitoring.
Polar
BrilliantHouse
Garmin
Coros
Aeac
Akumaka
Fitvii
Withings
MorePro
Amazfit
Timex
Moofit
Magene
Milavan
Hingso
Mindrose
Usmecbl