Refractometer box/holder

I ordered a refractometer from Aliexpress, so I neded a holder for it.

I designed in Fusion360 and printed on Anycubic Predator.

I put some sponge staff in it to safe the refractometer.

I use 4pcs 20x1.7mm magnets to hold the lid in place, and 2pcs M3 bolts for the back.