Customer service helped me identify the part. Perfect.

The last of the three toilets that we bought 25 years ago from Kohler has now been removed. They always had a tendency to leak and new flapper valves seldom solved the problem.

[This review was collected as part of a promotion.] A flapper is not just a flapper true many off brands will fit BUT they don't hold up and began to leak way to early. Having the right part and Kohler quality less problems long lasting leak free saves money in the long run.

I am so happy. I have never had a flapper such as this. It keeps the water in the tank.

[This review was collected as part of a promotion.] I found exactly what I needed and installed it myself!