... anti-fatigue transmission chain 20B-2 1.material:40MN/A3 2.standard roller chain 3.making as ... your sample duplex anti-fatigue transmission chain 20B-21.material:40MN/A32.standard ... bag,white inner box, then pack in standard export carton or wooden case,also can ... 520H, 530, 530H, 05MA, 05MB, 05MC, 06MC 2. O-Ring Motorcycle chains: 428SO,520SO,525SO,530SO3. Roller ...