Hay que tener cuidado por que calzan grande. El sistema de cancelación es muy bueno. All I can say is wow. The music just stuttered the entire time. That really has been the only hiccup with them. I will say that after a few hours I do have to take them off for a bit, but again thats my issue. Not pleased with the item at all. Bought for iPhone SE 2020. TLDR: After owning a $150 FitBit and a $35 LETSFIT, this tracker blows both out of the water. it?s not bad!