K&N Engineering RK-3931 RK Custom Air Filter Assembly

Custom filter assembly for Harley-Davidson engines. Increased air flow without sacrificing filtration. Designed to fit factory airbox. Million mile manufacturers warranty. Increased air flow. Increased performance. Washable and reusable Custom filter assembly for Harley-Davidson engines. Increased air flow without sacrificing filtration. Designed to fit factory airbox. Million mile manufacturers warranty. Increased air flow. Increased performance. Washable and reusable Street Legal in Most States. Not Legal for Use in CA and Other States Adopting CA Emissions Standards.