This is an enclosure for a mysensors-based CO2 sensor, built with an arduino nano and a senseair S8.
The radio and the arduino goes below the hollow insert, the sensor is mounted in the dome on the insert plate.
See video for how the plastic parts are put together. Mount the bottom part on the wall/mounting plate first, then mount the electronics and the rest in place, and finally glue everything together after testing. The parts do not snap together, you will need glue.
Don't solder legs on the bottom of the Nano, I couldn't find a better model for the video.
doesn't matter PLA
Print the top as a dome.
Print the sensor holder plate-down, legs up in the air
Print the bottom part opening up.