1″ Bore Sprocket Hub for 60T, 72T #35 Chain and 48T, 54T, 60T #40 #41 #420 Chain
72T, #35 Chain, (4) 3/8″ Bolt Holes on a 2 7/8″ Bolt Hole Circle, 8-3/4″ OD, & 2″ Center Hole. 60T, #35 Chain, (4) 3/8″ Bolt Holes on a 2 7/8″ Bolt Hole Circle, 7-1/4″ OD, & 2″ Center Hole. 54T, #40/41/420 Chain, (4) 3/8″ Bolt Holes on a 2 7/8″ Bolt Hole Circle, 8-7/8″ OD, & 2-1/8″» Center Hole.