Chrome plated. This is the Sidekick; your trustworthy companion in improving incoming air. The rear side of the forged billet and CNC machined filter housing is angled away from your knee; giving you additional leg room. Great example of functional design without losing esthetics. For the visual catch a translucent polycarbonate side window is used; with a special coating for long-term durability. The black synthetic high flow filter element is durable and wrapped in a stainless mesh. It is water resistant and requires no more than a rinse for cleaning. Oiling is not required. Note: Breather design is o-ringed at the heads; passes through the backing plate and is placed inside the mouth of the throttle body through proprietary shooter tubes. Note: A replacement clear polycarbonate side window is available as 936606. Note: The stock replacement air filter element is available as 708680.