... steel 2. color : blue, black, yellow and natural A series roller chainsSpecification:1. Simplex: 03C, 04C-1, 06C-1, ... 085-1, 08A-1, 10A-1, 12A-1, 16A-1, 20A-1, 24A-1, 28A ... Duplex: 04C-2, 06C-2, 085-2, 08A-2, 10A-2, 12A-2, 16A-2, 20A-2, 24A-2, ... -2.3. Triplex:04C-3, 06C-3, 08A-3, 10A-3, 12A-3, 16A-3, 20A-3, 24A-3, ... , black, yellow and natural industrial transmission chain (A series)