Sunstar Steel Front Sprocket 30913 Manufactured from case-hardened chromoly steel for the ultimate in strength and durability. Parkerizing surface treatment for rust and corrosion resistance. The excellent OE quality you expect from the SUNSTAR brand. Manufactured from case-hardened chromoly steel for the ultimate in strength and durability. Parkerizing surface treatment for rust and corrosion resistance. The excellent OE quality you expect from the SUNSTAR brand.