Arlen Ness Stage 1 Big Sucker Air Filter Kit M8 for TouringEach hidden breather is o ringed at the heads, passes through the backing plate and exits inside the mouth of the throttle body through the proprietary breather tubes Hidden Breather backing plate technology is a step up from original system Aluminum filter top plate has integrated filter mounting studs and directional air venturi for increased durability and performance Filter offers over 200% more surface area than the factory filter and features a