The rails for the VIDGA curtain system are attached to the ceiling by two flimsy plastic part and interconnected by another, equally flimsy piece of plastic. When I tried to join two rails, they were misaligned and twisted against each other, which looked horrible and had the added drawback of the curtains not going through the joint.
So I made these joints that can be plugged into the empty top holes in the rail - they fit tight enough to force the two rails into the right position. I left a little rim around the middle that prevents them from disappearing into one rail without connecting to the other. Therefore the rails are not flush against each other, but they still work well enough.
I just tell everyone that my curtains are airgapped, because that's more secure.
The author marked this model as their own original creation.