I took the watch for long distance running. Before that, I ran with a chest sensor, the belt rubbed the skin, so the choice fell on these. I was able to buy new ones for a much lower price. They have one glitch - the heart rate freezes at 86-91. It happened once at a half marathon, it was very unpleasant. I found a simple way on the Internet: you need to turn off the sensor and restart the clock. Well, always start running only after the heart rate sensor stops flashing. The second jamb happened after 10 months - suddenly an allergy from the strap began after 4-5 hours of wear. Either the pollen from the fir trees got in, or something, but this has never happened before. I read the forums - it happens with this model, and with all watches with plastic straps. Now I run, wrapping the strap with a bandage. after 2 months: fir pollen is to blame. After 2 months, I stopped wrapping the strap with a bandage, I run with the old strap, everything is fine, there are no irritations. Apparently, the pollen from the fir trees really got on / under the strap - he lived in the forest. True, the maximum wear time is now no more than 2.5 hours.