The attached 3D file features an air vent with a male insertion diameter of 152 mm.
The slats are angled at 45°, which is a classic design. A central reinforcement ensures the slats will not be damaged.
You can easily configure your own here (diameter, angle, reinforcement or not):
https://www.iteration3d.fr/en/templates/template-view.php?templateid=16
Fast and easy!
The author marked this model as their own original creation.