I wanted my air ventilation grill in color that matched my windows. So I copied my existing grill made by Fresh AB.
The models are for a 75mm pipe. Enlarge the model by 32% for 100mm, and 64% for 125mm pipes.
3MF files correctly scaled, can be found here: https://makerworld.com/en/models/200549
The author marked this model as their own original creation. Imported from Thingiverse.