@soti I have a Fitbit Charge HR, the newest model. It is not bad actually with measuring HR. I did a lot of research before purchasing it, and although it's only supposed to be accurate to 4 BPM, I always wear it when at the Doctors having my Blood Pressure taken and the HR reading on my fitbit is always the same as the reading on the BP machine so in that respect I am quite impressed. It is useful in managing my POTS and it has a handy meditation feature, but in hindsight I wish I had spent another £100 and gone for a more technical piece of kit that allowed me to set alarms for my HR, as this can't do that. I think the Fitbit is more of a 'fashion' piece, but it's not bad if you're just looking for a simple HR tracker without HR alarms.