Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
Very disappointed in these. We have two dogs using these and was very happy to find replacements much cheaper than in stores. I noticed the don’t turn much to lock into place. In 10 days 4 batteries have came out at some point I have even used loctite and no difference. They won’t stay in the collars.