roller chain for bike 1.Materials: carbon steel, stainless steel 2.Colors:blue,black 3.Small order accept A series roller chain Specification: 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 ...