The Box One 3/32" CNC Crmo Cog-Black is designed to fit Shimano compatible cassette hubs...and ONLY Shimano compatible cassette hubs. So no trying to sneak it onto a Campagnolo cassette hub! It works with 3/32" and 1/8" chains, is solid, heat-treated CNC chromoly, and has a wider inner base for firm, rock-solid contact with the cassette. The "chrome" graphics are actually a result of the whole cog being anodized black then laser etched to create the graphics. Neat trick!