a simple small stand for the round 41mm hygrometers from amazon, has a 4 mm hole for mounting it where you need it. there is lots of clearance to make sure there's not too much resistance so the fit's loose in case it dies and you need to replace it. even mounted face down, not sure why you would want to mount it that way, it holds fine. slightly refined but not too fancy. steep chamfer for easy print and use.