Sunlu coupler - M6 pneumatic coupler (Patreon)

This actually took many tries to get it solid, but that one has held up over time, print orientation was keyI recommend PETG for its elasticity over PLAprint with at least 3 walls/perimetersuse a brim if print fails, as it's bridging a relatively thin piece, but worth trying without first.Use a small piece of PTFE tubing (5~7mm should be enough)