To calculate the overall star rating and percentage breakdown by star, we do not 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.
It’s a good product. Heart rate seems to lag a little but that may be the same with others. I’m particularly annoyed at yet another proprietary recharging cable - and quite flimsy too. What’s going to happen when it breaks/is lost? I’m also scriptural that the band will last more than 12 months. The spare that comes with it is far too small to be of use for my arms.