Mercury lower unit in good used condition.  Housing and fin both intact and without significant damage.  Prop shaft rotates smoothly when the vertical shaft is rotated.  I am no lower unit expert so I am not sure what size motors and what years this fits.  I don't see any identifying part numbers on it.  I will answer any reasonable questions you have. I purchased a large inventory of used boat parts, this was part of the lot.  See my other listings for more boat motor parts, it will take me months to list everything.  See my other listings for more well priced, name brand items.  Calculated shipping or free pickup in State College, PA.  All boat motor parts are guaranteed to please or your purchase price cheerfully refunded.