I purchased a cover for Jacuzzi cartridge filter tank and the cover was 3/8" out of round. I was told the cover met manufacturer guidelines and therefore was not defective. I asked if I should pound the cover on with a rubber mallet and see what would happen and was told that was my decision. Since there is no doubt the unit would leak if I did that, I decided to send the cover back, but shipping cost is up to me. Since the cover is defective I don't undeerstand why I should pay to have it returned. I'd give this review 0 stars if that was an option.