I don't know if anyone can find this supplement for a Testovent 415 air flow meter (TESTO) useful. It went pretty well for me. If that's the case, I'll leave it here.

4 pieces must be printed and joined with screws. Alternatively they can be joined with adhesive.

In this case, I used PETG because the air outlets I measured were at a certain temperature. If cold air is measured, PLA could be used perfectly.

To improve the tightness of the supplement, it is advisable to add a self-adhesive rubber joint (EVA, neoprene or similar)

Additional material for assembly:

16 screws M3x10 DIN933 (ISO4017)

16 nuts M3 DIN934 (ISO4032)

32 washers M3 DIN125 (ISO7089)