I find it surprising that a we still need a chest belt to measure heart beats. I can put a finger on my wrist and feel every beat perfectly. Strange that a wrist band cannot do the same.
The chest band is still more accurate (and cheaper). It gets the minor variations in HR from beat to beat. When you get closer to your maximum HR your hard beat gets more even. HR variability gives more info.
M430 in my wrist. It has it's own optical HR sensor. It does not need H10 to measure HR. Polar H10 is the chest strap, it used electrodes with skin contact to measure HR.
When H10 is available and paired to M430, M430 uses H10 to get more accurate HR measurement data from the strap.
H10 works also alone with a free Polar app so you don't need the wrist monitor, although M430 has GSP and screen so it can measure also distance.
Right, but probably only when you're stationary. Try taking your own probably when you're walking or typing.