... 1. material: alloy steel 2. color : blue, black, yellow and natural B series roller chainsSpecification:1. Simplex: 04B-1, 05B-1, 06B-1, 08B-1, 10B-1, 12B-1 ... , 16B-1, 20B-1, 24B-1, 28B-1, 32B-1, 40B-1, 48B-1, 56B-1, 64B-1,72B-1.2. ... 3, 28B-3, 32B-3, 40B-3, 48B-3, 56B-3, 64B-3, 72B-3.Material: alloy steelQuality: With ...