The Arlen Ness Derby Sucker kit is Arlen's newest innovation to the V-Twin air cleaner market. This unique design includes a 5-hole mounting system that allows you to bolt on your favorite Twin-Cam derby cover for endless design possibilities. Pre-oiled filters come in two variations... the standard red Ness filter or the NEW "SS" stainless steel jacketed configuration. Kits also include Ness' patented hidden breather Big-Sucker backing plates available in chrome or powder coated black wrinkle finish.