Curtain Rod Mount from (The $2 Curtain Rod System - IKEA STYLE)
an 80 mm long version of the "The $2 Curtain Rod System - IKEA STYLE" RIGHTSIDE-_LARGE Which actually doesn't exist on his download page.
This version is extended from the wall a few more millimeters since my existing side hangers are about 80 millimeters from the wall.
I also expanded the hook in diameter a bit, to fit my rod.
I am using this as a middle rod support, but you can use it on both ends if you flip it in your favorite 3D editing program.
***UPDATE: I added the left side, so no need to flip on your own. Just download!