Spectre’s 14 inch outside-diameter by 4 inch tall Extraflow air cleaner assemblies come with a Spectre HPR air filter with red, blue, black or white media and a matching Extraflow air filter lid. The base is designed to fit carburetors and throttle body injection with a 5-1/8 inch neck. The Extraflow lid is designed to help increase air flow over a standard closed lid.