The K&N Drop in Air Filters 33-2985 is a high-performance air filter designed to replace the factory air filter in a vehicle's air intake system. It is made with multiple layers of oiled cotton gauze, which allows for increased airflow while still providing excellent filtration. This drop-in filter is designed to fit directly into the existing air box without any modifications, making it easy to install. It is washable and reusable, providing a long-lasting and cost-effective solution for improving engine performance and fuel efficiency.