Had purchased a set of hydrometers to monitor the humidity of the container where I store my filaments. Rather than opening, closing, etc to see what the humidity level is, I decided to create a mount that would be attached to the lid. But the way the monitor casing is, it would be difficult to use double sided tape or even magnetic strips. I also wanted an easy way to remove the monitor to change the batteries as I am not sure how long the monitor lasts on 1 set of coin size battery.

I created 3 versions depending on what fits your need. On version has a small lip so the monitor can be easily removed if you decide to use double sided tape and also if you want it in a vertical orientation so it can easily be removed.

Hygrometer: https://www.amazon.com/dp/B0CRHQ51XQ?ref=ppx_yo2ov_dt_b_fed_asin_title (size of monitor is 50.25mm x 50.25mm x 15.5mm)

I had another monitor to do some baseline testing and 3 out of the four were consistently the same readings with each other and maybe 1-2% points off, while the fourth was off by about 2-3% points.