Arlen Ness Big Sucker Stage I Air Cleaner Kit For Harley Performance is something that King of Choppers Arlen Ness is quite familiar with. The Big Sucker air cleaner kit is the most potent and best-selling product available on the market, hands down. The Big Sucker is made, quite simply, to provide your engine with the most airflow possible for optimal performance. According to tests, you can achieve horsepower gains of up to 21 just by installing a Big Sucker kit. Features: Aluminum filter top plate replaces the traditional stamped steel filter plate and has integrated filter-mounting studs which eliminates the need for additional filter mounting hardware High performance filters are made from black pre-oiled cotton for the best in airflow and filtration Filter is washable and reusable Smooth radius air inlet directs unobstructed air flow straight down the throttle body