This is a simple mount for the popular Xiaomi Mijia Bluetooth thermometer/hygrometer inside a drybox. While the model is original, it is loosely inspired by this design from Serbitar:
https://www.prusaprinters.org/prints/108118-xiaomi-mijia-bluetooth-hygrometer-drybox-mount
Open source firmware: https://github.com/pvvx/ATC_MiThermometer
The author hasn't provided the model origin yet.