Uni Air-Box Vents. Uni's foam filtered air vents increase the amount of air to the air filter for a better air supply and improved performance. The removable foam element may be cleaned and re-oiled for years of dependendable service. For street, dirt and atv applications, 2 or 4 stroke motors. Re-jetting may be required depending on application and number of vents installed. Easy to install, simply drill hole in air box and press in. Sold in pairs.