When I created the ventilation for my printer cabinets, I needed a way to connect the ductwork to it and turn the airflow on or off when the cabinet wasn't in use.

I created this as a 2 part coupler with which the 4in ductwork can easily be connected to.

The hole cut into the cabinet can be square and somewhat sloppy as it will be sandwiched between the coupler and the inner gasket by bolting them together.

The threaded plug makes it easy to cut off airflow to redirect to other cabinets that are in use.

Print using standard settings. No support is required.