The long-missing heart rate monitor is finally available on the Casio WSD-F21HR smartwatch featuring Wear OS. However, the device is quite expensive.
The Casio WSD-F21HR has a heart rate monitor, finally - Android Authority
CASIO WSD-F21HR - Test 4 Outside
CASIO WSD-F21HR - Test 4 Outside
Casio's Newest PRO TREK Smartwatch Finally Has Heart Rate Monitoring
Casio Pro Trek Smart WSD-F21HR with Heart Rate Monitor
CASIO WSD-F21HR - Test 4 Outside
The Casio WSD-F21HR has a heart rate monitor, finally - Android Authority
CASIO WSD-F21HR - Test 4 Outside
Casio Pro Trek Smart WSD-F21HR with Heart Rate Monitor
The Casio WSD-F21HR has a heart rate monitor, finally - Android Authority
Casio Pro Trek WSD-F21HR review
CASIO WSD-F21HR - Test 4 Outside
Casio WSD-F21HR Review, Pro Trek Smart