2cylindrical shape steel housing w/ two inernal flyweights, one end of housing open, other end w/ 20 tooth spur gear, 1.375 in. O. D. Of gear, 1.250 in. Pitch dia, 16 diametral pitch, 0.750 in. Bore dia, 3.565 in. Largest housing dia, 3.456 in. O/a lg