3/4" Bore Brake Drum Sprocket Hub
For 60T, 72T #35 Chain and 48T, 54T, 60T #40 #41 #420 Chain
4" Outer Diameter, 3/4" Bore with 3/16" keyway & 2 Set Screws
(4) 1/4" Bolt Holes on a 3.228" Bolt Hole Circle, (4) 3/8" Bolt Holes on a 2 7/8" Bolt Hole Circle