This is a simple meter holde/case for  an often used humidity/temperature meter which you can buy at places like [AliExpress](https://www.aliexpress.com/item/33037396704.html).

The meter just fits in there and it can be mounted with a screw anywhere. At the underside is a small gap that allows you to remove it from the case when necessary.

I use this in a apiary to have a meter for temperature and humidity for logging.