by dsmith1960, published
This flag holder will fit new-style cubical walls that are approximately 3" wide with a 1/4" top plate. The hole is 2" deep and slightly larger that 5/16" (0.312) in diameter.
This was printed on a Cube printer without support. The hole was obround when printed so I used a 21/64" (0.359) diameter drill bit to make the opening more round.