Glass Whiteboard Magnetic Eraser Holder

I have a clear glass whiteboard which is (obviously) non-magnetic, but I missed being able to use the various accessories designed for regular whiteboards, such as magnetic erasers. This design clips onto the side of a glass board and includes a couple of small magnets so that a magnetic eraser will stick to it. This gives you that floating look (and ease of use) which I prefer over a shelf or bucket-style holder. 

The clip is designed for a 4mm thick glass board, with a little tolerance. The magnetic aspect is provided by two holes on the rear for 3mm x 6mm magnets. This orientation specifically works with the eraser I have (Amazon link) but I would imagine it should work with most similar designs - YMMV though, I would test with a magnet before printing. 

There are two versions, one with a small shelf to catch any dust that falls off, and one without. The non shelf version should work at any orientation, the shelf version would need to be mirrored in your slicer to fit on the left side of the board. 

I printed in regular PLA, other materials should work as well. No specific settings required but I'd recommend printing it standing up, and therefore adding a brim unless you are very certain of the stability of your bed :) The model is tall and may fall over if the bed grip is insufficient. I had no problems with a 1cm brim. I'd also suggest adaptive line height to keep the curves smooth around the magnet holes. The holes print on my printer exactly right for a snug friction fit - but you may need to adjust depending on tolerances. Note that when in use the magnets are trapped by the glass, so it's not a problem if they're a little loose in the holes.

I included STL and STEP in case you need to tweak. Please post your makes! :)