You know those small round cheap hygrometers / humidity & temperature meters? It's the one you find online for dirt cheap if you look for LCD hygrometer on aliexpress/amazon.
This is a very minimalistic mount you can use to mount them on your prusa mini inside an enclosure. You use two t-nuts (metal or 3d printed) inside the 30x30 aluminium extrusion to mount it.
You can of course also glue it, tie-wrap it or mount it to something else that has an aluminium extrusion.
Be smart and attach the mount, before you put the hygrometer in it. This makes it easier to screw it in.
The fit is tight. If it is too tight for you, scale it up a teeny weeny bit.
Should print fine with almost any print settings. I put mine flat on the "ring" on the bed. I printed with 0.2mm height speed settings without any supports or brims.
The author hasn't provided the model origin yet.