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.
Bought this for work, it is excellent at keeping my tea piping hot. So hot I have had to take the lid off to cool it down. Keeps tea hot for 10 hours easily, only negative is the lid doesn’t line up well, often the handle is in the way of this sipping whole. I would buy the Thermos without handle to eliminate this issue.