Screwing it in was a bit of a hassle bc the bottom portion where the screw sits in place are like wings that spread the more you try to tighten it. I don't have a Kohler toilet so maybe it would work better on one of those. It fits, but it is a bit loose. Not where it'll affect anything so I'll keep it. I also don't think I'm going to return a toilet seat that has been on a used toilet even if I scrubbed it down before placing the seat on there.