• Engineered and proven to give your engine maximum airflow for more horsepower & torque
• One-piece aluminum backing plate features our patented hidden breather technology, each breather is o-ringed at the heads and exits at the mouth of the throttle body eliminating the need for any external hoses or hardware for efficient engine breathing
• Each backing plate contains a smooth radius air inlet to direct unobstructed airflow into the engine
• Performance air filters are available in red pre-oiled cotton & synthetic filter elements
• Standard performance filters are constructed from red pre-oiled cotton and are washable/re-useable
• Synthetic performance filters are constructed from black synthetic filter element that is wrapped in a stainless steel jacket. Washable/re-usable, do not require oil and are water resistant which in most cases eliminates the need for a rain sock
• Backing plate is finished in black powder coat
• Each Stage I kit includes one-piece aluminum backing plate, performance filter, gaskets, necessary hardware, and Knuckle Stage I Cover

Fits: 1988-2020 Harley-Davidson Evolution Motors