Mercury 821354A2 18-4531 Impeller Kit 25hp 30hp 40hp 50hp 4-stroke Steering Helm Parts This would have been found

This would have been found on some early (1960's) 6cyl Mercury applications  700 6cyl 70hp

Various 40hp & 50hp Outboards 1992-2001 with electric start

They should match yours

THE LIST COMPILED BELOW IS JUST WHAT IS ON THE PACKAGING WHICH I ASSUME IS FROM THE 1980's so may or may not be relevant to any outboard produced after 1980) If you are replacing the same type/color of stabilizer the model number is printed on the edge of the fin

from 1964-1989 - (2-Piece Rear Oil Seal) - 1990 & up was 1-piece and not the same as this)

Mercury 821354A2 18-4531 Impeller Kit 25hp 30hp 40hp 50hp 4-stroke Steering Helm Parts This would have been foundPart Number(s) Included Sierra 18 4531 Impeller Kit (Sierra 18 3057 47 85089 3 Impeller) Replaces Mercury Mariner 821354A1 > 821354A2 Impeller Kit (Impeller Plate Gaskets) Applications (from manufacturer) Mercury 25hp (4 Stroke) Mercury 30hp (2 Cyl) Mercury 30hp (4 Stroke) Mercury 40hp (2 Cyl) Mercury 40hp (3 Cyl) Mercury 40hp (4 Stroke) Mercury 50hp (3 Cyl) Mercury 50hp (4 Stroke) Mercury 50hp Bigfoot (4 Stroke) Other Information Please double check