50-1 Roller chain: 1, Material: 40Mn 2, Color: Blue 3,Standard: ANSI, GB, ISO, ... This kind of chain has many models. 50-1 Roller chain with 2 attachments' specification:1, Plate material: 40Mn; Pin: ... 40Cr; Bush and roller: 10# steel2, Color: Blue. And natural ... + wooden case6, Delivery time: 50 days 50-1 roller chain with 2 attachments