Verus Engineering Drain Back Kit Subaru WRX FA20 Engine

By using our add-on AOS Drain Kit, the AOS can be used for years of service-free life. 

There is no longer the need to drain, open up the unit, or do anything but drive the car! This is optional, only those that want this function should purchase this add-on. The AOS works like a typical drain-style unit out of the box.