These are probably fine if you are in fact installing them on a Kohler product. I bought them
for a very old Speakman Kent shower diverter because they're the only ones I could find that are proper diameter and thread. Problem is that the little shoulder between the threads and the seat is a just a hair too big. They just barely fit in to install them, but if one ever needs to remove them again you'll be effed. (fortunately, I did this on the workbench and not in place)