K&N Air Filter Ya-4504 K&N Air Filters are meticulously designed to achieve nearly unrestricted airflow while maintaining crucial filtration levels essential for engine longevity. The key to their effectiveness lies in the distinctive characteristics of the filter medium, originally developed by K&N through the challenges of desert motocross racing. These air filters feature a high-flow cotton gauze medium that is not only washable and reusable but also crafted to endure the entire lifespan of a motorcycle engine. Constructed with four to six layers of cotton gauze placed between two sheets of aluminum wire mesh, the media is pleated and oiled to augment its filtering capabilities and overall performance. Developed for environments demanding maximum horsepower, enhanced acceleration, and protection against dirt and dust, K&N Air Filters significantly increase the airflow to the engine. The end result is an air filter that is washable, reusable, and provides lasting engine protection throughout the life of your ride. Features: Washable and reusable Designed to last the life of the engine Constructed with four to six layers of cotton gauze placed between two sheets of aluminum wire mesh Pleated and oiled to augment its filtering capabilities and overall performance