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.
I bought this to take my lunch to work as well as store leftovers in the fridge. It seals OK when standing still however I was disappointed to discover that it isn't watertight, leaving a huge mess in my bag when I took my lunch to work. Will not buy again.