CNC-machined from long-wearing 7075-T6 aluminum alloy Designed to fit Shimano-compatible cassette hubs and have a 5mm wide inner base, giving a more solid interface with the cassette body Alloy cogs are anodized black with laser-etched graphics 13T x 3/32` 13T Black 8gUPC/EAN/GTIN: 639266092360