Premium Aluminium oil return flange for AirWerks S400SX / S400SX-E turbochargers Oil drain flange BorgWarner AirWerks S400SX / S400SX-E series Oil return flange for AirWerks S400 Turbochargers Fits for S400 S400SX S400SX3 S400SX4 S400SX-E Milled aluminium oil return flange for the BorgWarner AirWerks S400 / S400SX-E Series turbochargers. This S400 / S400SX-E oil drain flange now has an o ring groove and supplied o ring for sealing. You no longer need a gasket to use this flange. The hole in the middle has a 3/4" NPT connection. Material: Aluminium Fits for: S400 / S400SX / S400SX3 / S400SX4 / S400SX-E