My husband uses it while running and he says it's awesome.
Pairs easily with his garmin watch and is comfortable to wear while running.
Gives extremely accurate information, and is perfect for serious training.

Ordered this on a pinch before an Ironman last year. So far I've been running this HRM for almost 14 months for all of my cycling and running (approximately 330 hours of use). I only use it for my swims on races (2x70.3 and 1 sprint so far). I have only had to change the battery one time in the time I've owned it. Data seems very accurate and the strap is comfortable and holds up. I even throw this thing in the wash with my bike clothes on occasion, and haven't had any issue (this is not recommended by the manufacturer, but I found it easier). The elastic material seems to be fatiguing slightly on the sides, as it seems creased, but all functions well. I admittedly don't take very good care of this HRM, but it has held up and has been bullet proof to me. My only gripe is that I can't replace the strap; but I think I have plenty of life left. When it needs to be replaced I will definitely commit to the newer model with the replaceable strap.

All the functions off this strap worked well in running, rowing, and indoor exercise settings. It was comfortable and stayed in place. The only negative is that the past two bands that I have purchased have only lasted a little over a year before the sensor area becomes unglued and it stops working. I only rinsed the strap under warm water and occasionally used soap.

Product lasted a little over a year with pretty much daily use. When it was working it was pretty great, but I've gone through all the troubleshooting steps and haven't been able to get it operational again.

Spoke with Garmin support and they are sending me a new one since this one stopped working.

Update (8/22): Contacted Garmin Support dept and they replaced the HRM-pro for free. Explained what happened and provided proof of purchase (~6mo outside factory warranty period) and they sent a link for a no-charge order for a new unit. Upgraded to 5 stars for the customer service.

Original review (~6/22): I'm a garmin fr935 watch user and avid runner. I bought this as a better & more reliable means of tracking HR than the ohr/optical sensor on the forerunner series. The watch based ohr readings would fluctuate based on watch band tightness, wrist location, and weather (skin temperature?).

This hrm-pro was much more reliable with the added bonus of the running dynamics metrics. I wore this pretty much daily since Feb '21 for ~1hr/day. The Connect app battery meter for this was a joke and I never saw it go lower than 100% full. I read about the battery change process potentially leading to early failures but thought I was pretty careful in the process. I changed the battery on this ~3-4 times since new but the last time was likely the killer.

A small crack developed on the base plastic near one of the screw mounting points that must have caused a leak. Washed it recently, let it dry then no more pairing. Opened it up and noticed condensation in the battery compartment so decided that it was terminal enough to do "major" surgery to investigate. The pictures tell the story:
water got in behind the main board and shorted out some components. Maybe if I washed this without the battery in (cover on) and then let it dry out I could have got a few more months out of it? This seems to be a pretty common problem with these series of garmin hrm units (pro, tri, run, etc) so buyer beware.