Arlen Ness Knuckle Stage 1 Big Sucker

Big Sucker™ Stage 1 air cleaners are 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

• Knuckle Stage 1 Air Cleaner Cover 
• Increases Horsepower & Torque 
• Patented Hidden Breather Technology 
• Pre-Oiled & Synthetic High Performance Filters
• One-Piece Aluminum Backing Plate 
• Radius Air Inlet for Unobstructed Airflow  

California Air Resource Board: Executive Order D-639-10