Product review (5 stars): This fits perfectly.
This is identical to the one I had and that was disintegrating and allowing small spoons and other stuff fall into the grinder. I also bought the sound proof part and that fits fine underneath this but I did not noticed any difference in sound. It is an obstruction to the flow  but with the tap on full the water does not accumulate in the sink. The size of the object is listed as 5 inches but that is not the diameter, which is around 3 inches.