For over 25 yrs, Walker Engineering made THE best Air/Oil Separator money could buy. Unfortunately, in 1997, Walker was so busy supplying the OEM diesel & marine engine mfgs with AirSeps, they just didn't have time to build them for aviation and ceased production. Airwolf acquired all the rights and STCs from Walker Engineering and has expanded the elligibility listing to include all piston powered arcraft. If it burns avgas, then we have an air oil separator approved.NOW AVAILABLE The MiniAir Sep - Price is $450 complete - an effective air oil seperator solution only with only a 3" diameter and 4" tall. Call to find out more.