AOS Drain/Crank Case Vent Line Kit - Mk5 Toyota SupraOVERVIEW With the addition of our AOS Drain CCV Line Kit, the AOS can be used for years of service free life while ensuring the intake tract stays oil free. By routing the crankcase vent through the AOS instead of going directly to the intake, the oil in the air is now captured by the AOS. This is an optional addition, only those that want this function should purchase this add on. The AOS works like a typical drain style unit out of the box. WHAT IS