... treatment: Oxide black, galvanization, nickelizing, chromeplating6. Model: type A, type B, and type C. Single, Double, Triple35B 10T~80T, 40B 9T~90T ... quenchingSurface treatmentOxide black, galvanization, nickelizing, chromeplating, sandblasting Model Type A & Type B, Single, Double, Triple - 35B10-80,40B9-90 ... ,24B9-90,28B9-76,32B9-76 PackingPlastic bag+plywood case/Pallet sprocket transmission parts