This is a holder to slide a 1" x 6" strip of paper. Holes are embedded inside the print to place 3mm rare earth magnets making these great for placing on white boards.
My son uses these at home to keep track of sports standing on his white board.
A pause will need to be added to the print at around the 2.9mm mark so that the magnets can be placed inside.
Alternatively, you can use adhesive magnet tape on the back.
The author remixed this model.
Modified dimensions for more general use, as well as for use with magnetic whiteboard.