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.
Excellent quality, I can fit my wellies and walking shoes in bag and waterproof trousers in pocket in back. Beautiful design. Gave 4 stars not 5 as I thought the zip might have been a little sturdier, but so far no issues.