Keeps damaging particles from entering the engine and causing increased engine wear, Improves engine response time Protects the operational performance of your engine, Reduces ecological footprint through fuel economy, Boosts fuel economy by 6% to 11%, 98% Efficiency Against Rocks And Other Debris on the Road, Part Reference Numbers : 88117 XA4731 CA7421 AF7421 AF992 PA4731 A24731 46117, Kit Includes: 4x Air Filter, Kit Variations: K57-100121 K57-100414 K57-100997 K57-101476 K57-101856 K57-102236 K57-102616 K57-102996 K57-103376 K57-103756, Part Reference Numbers : 88117 XA4731 CA7421 AF7421 AF992 PA4731 A24731 46117