The small Kubota models, the B5000, B5000E, B5001, B5001E have 6-ribbed PTO shaft with good rotation direction, but size of the shaft is different from the standard. This is the easiest and cheapest way to adapt to standard 6-ribbed. Simply place the adapter on the shaft-stub, and hold in place with, using existing holes. Shaft outer diameter (standard 6 ribs) 35 mm. The outer length of the cylindrical sleeve is 57 mm. The internal depth is 42 mm. Small rib outer diameter 28.5 mm, inner 22.5 mm.