Used Original Mercury A/B Drive Shaft. Part Number 45-20909.  Used with the KG4H, KG7H and unconverted Mark 20H racing engines.  The shaft is 18 9/16 inches long, it shows wear in the crank end splines, on the drive shaft seal area, in the ball bearing area and the lower needle bearing area.  Recomended for display engines only and not a running engine.