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.
Would have given a solid 5 star but the courier they chose was unsatisfactory. Fedex couldn't deliver at my doorstep while other courier could, all the products i ordered along with this. I've been using a wide range of wavex products at my car wash center and couldn't find a better product than this to date. Works great, pleasant aroma, highly concentrated so its very economical. Recommended