K&N Replacement Round Air Filter for 13-14 Audi RS6/RS7 4.0L V8K&N washable, reusable High Flow Air Filters feature a state of the art design of layered, oiled cotton media engineered to improve airflow and capture contaminants, and are designed to provide an increase in horsepower. Each performance air filter is reusable, engineered to last for the entire lifespan of your vehicle, and backed by K&N's 10 Year Million Mile Limited Warranty. K&N drop in replacement filters are designed to install easily into your