Hi i am selling this 20”standard rotation lower unit that was removed from a 1999 mercury 40 2 stroke carbureted motor its in good shape shifts nice and smooth and oil didn’t show any signs of water intrusion and magnet didn’t show any signs of excessive wear this will fit 2 stroke motors 40-50Hp maybe others I highly recommend changing out the water pump impeller before using this unit please feel free to ask any and all questions thanks