About this 3D model
This is simply a cover for the original cup of the Ultra airbrush from Harder & Steenbeck. Printed on a Bambulab X1C, the inner diameter is slightly larger than the measured diameter of the cup (22.38mm/0.881in) so that it stays in place tightly. Warning : It seems it doesn't fit with the 2024 airbrush's cup (thanks T.I.M for this precision)