Miokycl 410 28T Bike Chainring 28T Bike Sprocket Carbon Steel Bicycle Chainring Replacement Parts1. Carbon Steel Material: The 28T bike chain is made of carbon steel material, which is sturdy and durable, not easily damaged, and can be used for a long time.2. The Optimal Tooth Diameter: The 28T 410 tooth diameter of the bike sprocket makes it an id..