For 1974-97 Johnson/Evinrude 2-cyl, 40 Hp outboards.
Hub uses key 47-01407
ID: 15.875 mm | OD: 50.8 mm
W: 19.05 mm | 6 blades

also crosses with:
Sierra: 18-3366
GLM: 89990
Mallory: 9-45212