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.
It's quality is not as expected and the item looks so cheap except 2 masks. As mentioned in the description the log of the barandnis missing in all the masks. Looks local quality mask is also mixed on the products. This not value for money. I am very disappointed with he products.and it's says free size but it suitable only for kids.