Up for sale is UNI AIR FILTER HONDA DIRTBIKE NU-4141ST. The vendor part number is NU-4141ST. Please read title to know what you are getting. The catalog decription.... is UNI AIR FILTERS.Uni air filters are unsurpassed in airflow, dirt stopping and overall performance.The produce more horsepower and more torque than any other air filter.Uni's revolutionary two stage air filter is the only filter that comes apart for maximum airflow and ultimate cleaning.To complete the winning combination, apply Uni oil and Uni cleaner.