W20 M20 20/150 Female to M12 8mm pipe Adapter Brass adapter to connect 8mm pipe to motorhome standard regulators with M20 external thread. It fits most of Cavagna, GOK and Truma regulators. It allows to connect underslung tank or any gas source to the regulator using 8mm copper or 8mm fiting for flexi pipe. The adapter comes with compression fittings and it works with 8mm copper pipe or 8mm flexi fittings. The internal threads are M20 .