Local tractor club meeting last night, one member said, " I don't know, but have a pair hanging in my shed". Another member said he did find the number doing an internet search. He said they were listed as part of a fertilizer attachment for a JD planter. I have no experience with JD planters, but looking at it I would suspect the rod attaches to the planer frame and the "cup" goes over the bottom end of the fertilizer drop tube, either to hold it in place or to keep dirt clods, etc. out of the tube.