Black anodized one-piece aluminum backing plate. Used with OEM air cleaner cover with single central bolt (excl. 08-17 Dyna; see note). The Big SuckerT Stage I performance intake adds horsepower and torque. The next generation patent-pending hidden breather system is O-ringed at the heads; passes through the backing plate and exits inside the mouth of the throttle body through proprietary shooter tubes.- Without cover – Takes all Arlen Ness Stage air 1 cleaner covers – Takes a custom round air cleaner cover with central mount hole; minimum ID 6-1/4″ (159mm) – Increases horsepower and torque – With black pre-oiled air cleaner element Note: 08-17 Dyna will require a custom outer air cleaner cover with a minimum inner diameter of 6-1/4″ (159mm).