To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
Does not fit very well. Uses cheap flexfit band which irritates the skin ... Now struggling to get a refund, post office records show they have received the item back ...they are denying they have it .. not good