An oil drain adaptor for the smaller 38.1mm bolt-spacing turbo drain flange, terminating in an AN6 connection. It suits the compact turbochargers commonly fitted to four-cylinder conversions, where the standard cast drain tube almost never lines up once the turbo has been repositioned on a custom manifold. Bolting this on gives you a threaded AN take-off so the drain can run in flexible hose along whatever path clears the block and chassis. Because the drain relies on gravity rather than pressure, keep the run short, continuously downhill and free of tight kinks, and use a fresh gasket on the flange face.