I have to ding the rating because my pump could not achieve the advertised high vacuum. Not sure if there is a problem with only my pump or if I need to invest in a two-stage pump to get a faster water evacuation. Perhaps another user could tell me if their pump works better.But I am reluctant to return this product because I think that the vacuum chamber alone is worth the investment. High quality stainless steel with silicone seals and I could use the pot for cooking when I don't need the vacuum.