Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Theses masks are extremely thin and fall apart at the seam if your not careful enough. They're lightweight and comfortable but only strong enough for single use. I was very disappointed in their appearance when I received mine. They look nothing like the advertisement photos. They look very cheap, wafer thin and poorly made.