duplex anti-fatigue transmission chain 20B-2 1.material:40MN/A3 2.standard roller chain 3.making as your sample duplex ... , 428H, 520, 520H, 530, 530H, 05MA, 05MB, 05MC, 06MC 2. O-Ring Motorcycle chains: 428SO,520SO,525SO,530SO3. Roller chains ... ,SC4,SC5,SC6,SC8,SC105. PIV chains: A0,A1,A3,A4,A5,A66. O-ring chains and xw-chains: 420 ... .Oiling11.Greasing duplex anti-fatigue transmission chain 20B-2