This is the coupling used on John Deere Waterloo built two cylinder tractors that are equipped with power steering. We precision broach alloy steel stock and machine to size. They are then casehardened. A steel rivet is then installed to keep the coupling centered. We then put on a zinc chromate finish for corrosion resistance. These couplings have a slightly tighter tolerance to reduce wear by running with a tighter fit. They will fit original John Deere shafts as well as our own shafting. See our other offering in KITSat part number GP-AF1902RKIT for additional savings.