STC-1000 is a nice little temperature controller that can be used to control both a heater and a ventilation in an enclosure. 12V and 220V versions are available for 10-15 EUR (Amazon) or $3-5 (AliExpress).
This box is designed to be mounted directly on an enclosure with M3 screws.
Print in PLA or PETG, 0.4 or 0.6 nozzle. No supports required.
The author marked this model as their own original creation.