Console holder for curtains. The picture displays the printed part in grey (PETG) with the original part.
Fits for ~13mm tube, my tube measures 12.8mm.
The holder can be taped by strong double side tape directly to a plastic frame of window (this is the original purpose) but it can be also screwed to a wall or a wooden material by 3mm diameter screws.
It's not an easy task to remove bridge supports completely when printing in PETG as you can see on the picture. It would probably require some sanding and / or sharp knife cutting to get rid of it completely.
The author hasn't provided the model origin yet.