You need to get power and filament inside an printer's enclosure easily but you don't want air to get in/out. So you can create a big hole in the side of the enclosure and insert this printed part to make a good seal. Source code is available so you can modify diameters.

Clamp is bigger than 180° so it will snap on and hold tightly.

Print the clamp in PETG for higher flexibility (avoids breaking). Don't use PLA since higher temperature in enclosure can soften it easily.