Increased filter area increases airflow and horsepower. Unsurpassed in airflow, dirt stopping, and overall performance. The GYTR® UNI Air Filter can be easily washed and re-oiled. Designed to work with the Billet Air Filter Adaptor Plate. The Pro Design Filter is designed to work with the RRP air box system or Pro Design adapter plate. The Pro Design filter is shorter than the GYTR allowing more room when using longer intake tube. (RRP system).