Photo Frame for Polaroid Hi-Print pictures, and confirmed it will also work with Instax mini, and more than likely the Zinc based ones as well.
Included a second -optional- back plate that can be used with up to three 15mm magnets.
This model has a 10% infill (pictured), I have modified the infill as low as 6% to get larger honeycombs with good results. The frame is a little “squishier” at 6%, but the solid backing firms it up great.