These complete high performance air filter kits include a 20% larger air filter than Stage I kits, a billet aluminum or stamped steel outer cover and patented Big. Sucker backing plate. Eliminates the need for banjo fittings, hoses, and clamps. Breather passages exit at the mouth of the carburetor/throttle body, creating a virtually closed-loop system. Pre-oiled filter element available in standard or stainless finish. Backing plate offered in plain, chrome or black finish.