John Guest Stem To Tube Adapter

This adapter can be used to reduce a 12,7 mm coupling to 9,5 mm. This means that the insert has an outer cross-section of 12,7 mm and the hose insert can fit a hose with an outer cross-section of 9,5 mm.
The fitting can be used if you do not want to use a python tube but to return the water to the waterbath with a 9,5mm tube.