Garmin HRM-Run Versions - Black vs. Red

Can anyone tell me what the difference is (if any) between the HRM-Run with the gray strap/black transmitter and the version with the black strap/red transmitter?

Thanks!

It is incredibly confusing but basically you have:

Garmin Heart Rate Monitor Soft Strap - Black/Gray BUT no runner icon on the front of the transmitter - this is just standard HR Monitor

Garmin HRM Run - Black Gray. HAS runner icon on the front of the transmitter - this has the extra features like cadence, vertical, etc. I got one packaged with a Garmin 620.

Garmin HRM Run - Red / Black. HAS the extra features like cadence vertical etc. I believe this was just a rebrand to make it less confusing and distinguish itself further as a premium product. Regardless, it is the newer device. I got one packaged with my Garmin 735xt

Thanks Thomas!
Doing some research it appears the main differences are the gray transmitter has a water rating of 3 ATM and the red transmitter has a water rating of 5 ATM. However, the transmitter for the gray version is detachable from the strap - which should make it easier to clean. The red transmitter is affixed to the strap.
However, it sounds like they function the same, which was what I was most concerned with.
I appreciate the assistance!

I own the black HRM run, and would suggest getting this one over any model that is attached to the strap. When the strap wears out after 12-24 months (gets too stretchy, or stops transmitting heart rate well because the fabric/pads loose some of their conductivity) you can replace the strap with any number of easily available straps for <$20 from Amazon, etc, instead of spending $50-100 on a new monitor/attached strap. Both my Wahoo Tickr and Garmin HRM Run have outlasted 2 straps each. This is the reason I can’t bring myself to buy the HRM Tri or HRM Swim versions. I hate/can’t support planned obsolescence product design.

I’m currently using this Scosche one, and it works great! http://amzn.to/2i6XuZW

FWIW - I’ve tried all the older Garmin hard/soft straps, and in my opinion/experience, the optical HRM by Scosche (not a chest-strap - goes on your upper arm or forearm) is MUCH better in terms of long-term performance. My garmin straps always gradually start to fail after 6months, and are too unreliable to be functional after 12 months; my Scosche however is as rock solid as day #1.

The only ‘bummer’ about the Scosche is that for triathlon RACING, it’s annoying complicated to wear due to the logistics of swim/bike/run. In my last race I tried putting it on in T1, and then turning it on to pair on the road, but somehow, it just never locked onto my watch (despite never doing this ever, in practice) - could be from the many other garmins around me?

But in training, the Scosche has been hands-down better than the Garmin (and other) HRMs I’ve used for both bike/run.