KMC hairpin 12-speed KMC / Shimano / Campagnolo / SRAM Size: 1/2 X 11/128 DLC DLC Technology: Extremely Durable, Extremely Precise. Unparalleled durability is achieved through precision-hardened and meticulously polished pins and inner plates. Our DLC chains are coated with a diamond-like coating, providing a long-lasting, visually appealing black beauty. Furthermore, this coating creates an exceptionally smooth surface for excellent shifting performance.