Model: A & B Series link All with simplex/double/triplex Motorcycle chain connecting link Connecting LinkModel:A Series: 25, 35, 41, 40, 50, 60, 80, ... ,20B,24B,28B,32B.All with simplex/double/triplex Roller chain linkMotorcycle chain link 420,428,415,420H,428H,415H,520,520H ...