Arlen Ness Slot Track Stage 1 Big Sucker Air Cleaner Kit For Harley This Arlen Ness Big Sucker Kit with a Slot Track steel cover has an all-in-one backing plate with carb support and built-in breather tunnels. The patented Big Sucker technology has tunnels that exit at the mouth of the carb or throttle body to create a virtually closed-loop system for the best performance possible. The Finish Stage I kit includes an aluminum backing plate and Team Ness round tapered high flow synthetic air filter. Features: All in one backing plate features a built in throttle body support and built in breather tunnels Tunnels exit at the mouth of the throttle body to create a virtually closed loop system Backing plate has o-ring breather bolts and a radiused intake manifold Kit includes an anodized aluminum backing plate, Team Ness high flow air filter and all necessary hardware Stage I features a tapered round air filter and an anodized billet aluminum air filter cover with a slot track design