Arlen Ness Big Sucker Stage I Air Kit - Black Backing Plate - Red Filter 18-561 All-in-one backing plate features a built-in carb support and built-in breather tunnels at each head to decrease crankcase pressure. Each tunnel exits at the mount of the carburetor to create a virtually closed loop system Breather features O-ring banjo bolt seals and a radiused intake manifold. No oil hoses, no oil fittings, no leaking and no mess Stage I kit features a Team Ness High-Flow filter that accepts all 93-up oval or round O.E.M. outer covers All kits include a Big Sucker aluminum backing plate, Team Ness High-Flow air filter, chrome banjo bolts for Twin Cam and 93-Up EV2 Big Twin, simple instructions and all necessary hardware