Arlen Ness Stage 2 Big Sucker Air Cleaner Kit For Harley Twin Cam Arlen Ness, the King of Choppers, knows a thing or two about performance. The Big Sucker is the best-selling and most powerful air cleaner kit on the market - period. Simply, the Big Sucker is designed to give your engine maximum airflow for maximum performance. Testing shows that by simply installing a Big Sucker kit, horsepower gains of up to 21 are attainable. Big Sucker kits feature patented, hidden breather backing plate technology - this means the breathers are incorporated into the air cleaner housing itself. Gone are unsightly external hoses and hardware, giving your bike a super-clean look. Each hidden breather has a sealing O-ring at the heads and exits at the carburetor or throttle body inlet to provide efficient internal engine pressure relief. The Standard air filter elements are made one at a time using the finest materials available. Standard filters are all pre-oiled, and feature four layers of surgical-grade cotton to promote airflow and filter air effectively. The filters are hand-poured one at a time in a urethane body, unlike many other filters that are spun, which can leave a residue on the filtration media. The Stainless Jacketed Filter differs from the Standard Filter in two areas: The mesh supporting the gauze is made of a rust-resistant stainless steel as opposed to standard carbon steel, and the synthetic filtration gauze is in black or dark grey, rather than the pink/red hue of the Standard Filter. All kits include a Big Sucker backing plate, high-flow filter, chrome banjo bolts, gasket, hardware, and simple instructions. The Stage 2 kit differs from the Stage 1 by including a 20 larger air filter element. Note: Air cleaner images are for reference only. All kits on this page will include filter of your choice.