The model consists of two end caps left and right to give the roll ups a more polished look.
There is also a joiner piece so that if you mount two blinds side by side they can look more as one piece of furniture rather than just screaming “ikea doesn't make this size”.
I provide 2 “standard” sizes for the joiner, 10 and 20 mm. There is also a parametric fusion 360 file if you want to make custom versions if your blinds are spaced differently.
The author marked this model as their own original creation.