Chrome plated 10-Gauge outer cover. With chrome backing plate. Air filter element pre-oiled with black oil. Engineered and proven to give your engine maximum airflow for more horsepower & torque. The patented hidden breather backing plate is o-ringed at the heads and exits inside the mouth of the throttle body for a virtually closed loop system, eliminating the need for any external hoses or hardware. - Increases horsepower & torque - Patented hidden breather technology - Pre-oiled high performance cotton gauze filter element - One-piece aluminum backing plate - Radius air inlet for unobstructed airflow