Brass quick coupling with M6x1 thread. The couplings are used for air conditioning and in 3D printing are used to guide the filament in the bowden.
Use the Teflon ring to lightly insert and remove the tube.
Suitable for the dimensions of the outer d = 4 mm / inner d = 2 mm)
These couplings are used in copies of E3D Hotends and many other Hotends
Pneumatic connector PC4-M6 for 4mm*2mm tube
Straight fitting, M6 thread, Teflon ring, external hexagon D 10 mm
(Product can be ordered in 1 piece, photo is for illustration only.)