Arlen Ness Chrome Finish Stage I Big Sucker Kit with Standard Filter 18-501 Gain up to 12 percent more Horsepower by simply installing a Big Sucker on your bike! These kits are designed to be used with the stock air filter cover Sportster models require the purchase of a custom outer air cleaner These kits can be used as an exposed filter design when using one of our Stage 1 billet covers All mounting hardware included