Absolutely wonderful, out old check valve would make the loudest most horrendous thud you could possibly imagine, this one is silent, and I men silent, there's no thud or anything.  I bought two in case one every failed.  Also my plumber told me there's a code that's typically on a check valve which he didn't see on this one, he thinks if it were installed during our basement finish that the inspector (if paying attention) may not have passed it because of the code missing, however, we installed it after the basement was finished and now it's nice and quiet when the pump cuts off.