I don't know if it's a problem with the watches or the belt, but every time I have to reconnect. I mean, as if it's new. Although it detects the belt, every time I have to ignore the device and reconnect it. Now, as for the reliability of the measurements, I can't say. There is a difference with the watch, but I haven't measured with a cardiological heart rate monitor to have serious data to compare.

After 2 years of use and not frequent use, it started losing heart rate readings while I was increasing the intensity of the exercise, showing that the heart rate was dropping. Not reliable at all, I am disappointed with its quality. I tried using it with another strap but it had the same problem. I do not recommend it.

The product broke 8 months after I bought it, even though I took great care of it. Suddenly, the strap broke, so I took it to the dealership in Ano Glyfada for a replacement, and they told me that they have arbitrarily decided not to replace the strap, and therefore, the transmitter essentially has no warranty since it does not work without the strap.

I have no problem as long as I use it. I mainly use it for running and cycling with Garmin Epix Gen2. The strap is soft during exercise. The sensor is removable. All good.

It is a relatively good product, but if you change your workout program, the Bluetooth gets out of sync, and on the Xiaomi 13, you have to restart the phone to sync again. That is, if you do cycling and then weights, you have to follow this whole process

With occasional use and proper cleaning, it lasted about 3 years. At first, it started to show that it wanted to give up, and in the end, it couldn't even connect to any device.

I'm very sorry I bought it. Big mistake. I have had a Garmin for 4 years and it has worked flawlessly. My new phone couldn't connect to it and I bought a Polar. After 6 months it stopped working and it turned out that there is no warranty on the strap. And it costs 65 euros.It goes in the trash where it belongs.

Well.... after about 4 years and using it three to four times a week, it starts to lose the accuracy of its measurements that it had all this time.
Now I found the H9 for 50 euros!! Immediate purchase, very good strap.
There is also the H10 for 75 euros, but I will go where I know and in the next four years I will buy this one again.
Simply the lifespan is four years (in my case at least, with hand washing after each workout)

The Polar belts have by far the most reliable and stable measurements. I have connected it at times with grit pro x, with garmin 265, with paragon x treadmill, with android and iphone. I never had a problem. I have had it for over 2 years, with almost daily use, and it's like the first day I got it. Hand wash with soap or simply rinse it with water after each workout. I have not put it in the washing machine.

Flawless belt with accurate measurements and excellent build quality. I connect it to my watch (Garmin Fenix 7X Solar) and use it for running workouts (3-4 times a week) + crossfit and strength training. I haven't used the corresponding Garmin belt to compare, but I am so satisfied that I don't think I will switch.

The product is great and compared to the Apple Watch SE, it provides almost the same measurements. The one star goes for the privacy policy that *coerces* consent for the use of sensitive personal data.

Be careful to open it in your size before wearing it. I put it on and I thought it should be tight so that there is no chance of it moving, but after a month the slot where the hook goes to tie the belt had worn out. Other than that, it's great. Also, if it doesn't record pulses, it needs to be updated. If it doesn't update with Android 13 (MIUI 14), connect it to an older mobile or iPhone to do the update and then you'll be good.

I have had it for 4 months, so far, it works perfectly with daily extended use (cycling).
I use it with Garmin, I have no connection issues.

I have it for over a year, it is reliable in its measurements in combination with the mobile application

I use it 3-4 times a week for the last 5 months. It's great in signal quality, accuracy, and compatibility

The best market zone, after almost 2 years of almost daily use, works perfectly... far from Garmin.

I have had the zone for 8 months and I use it every day for running. Its measurements are accurate and the battery lasts a long time. Remember to disconnect the sensor from the zone after each workout to save battery power. It connects to a Suunto watch without any problems. I am completely satisfied with the purchase. I highly recommend it.

REVIEW UPDATE: After 13-14 months of daily use, the zone has started to lose its accuracy in heart rate measurement. Therefore, I am deducting 2 stars from my review, as I believe that 1 year of good functioning is too short for a product of this value.

The battery that it had when I bought it ran out very quickly (in 2-3 months). There is a slight difficulty in fastening the belt and it may take several attempts. It communicates well with the STRAVA app that I use and I can see in the app what I did without activating it (except for the POLAR FLOW app). Now the fact that they don't agree with each other is another issue!!!

All good, except that it doesn't have internal memory, so you have to use it with a smartwatch or mobile phone.
Update: after approximately 1.5 years, it often shows crazy measurements

It is simply EXCELLENT, RELIABLE, and value for money. The sensors of the belt just need to be well hydrated (I recommend ultrasound gel), otherwise it shows half the actual heart rate until you start sweating. I use it every day during my training. I will write how long it will last next time.

The only reason I don't give it a 5 is because suddenly, after about 1 year of use, it stopped connecting via Bluetooth to my phone (my phone doesn't recognize it) and thus it became basically useless! But it is very reliable and convenient!

Use in running, although I preferred a polar zone watch because I read (on foreign sites always) the best in terms of accuracy in measurements, endurance, etc. They were not wrong.. indeed a very high-quality zone with a detachable sensor which I remove every time I finish the workout to rinse the strap from sweat salts and spread it out to dry without any fear of the sensor getting wet and all that. The strap can also be put in the washing machine according to the company's instructions for anyone who wants to. Flawless measurements, not even 1 second delay in interval exercises on the track. It connects with ant+ to my watch while also being able to be connected to my phone via Bluetooth and to the treadmill!! And as for the price, it's the best at 70€

I have it for a few days but it seems to be very expensive and directly connected to the Polar Application. They want to fix the App a little bit (e.g. it doesn't have daily workout)