This three piece adapter set is designed to work with 100mm (4 inch) ventilation ducting.

This allows you draw cool air from a window mounted Air Conditioning unit, transport it through a 2cm x 20cm gap and then back via 100mm round ducting.

Print instructions

I printed this with a .6mm nozzle on a MK3S with grey PLA and .40mm layer heights.

This reduces time and increased strength over smaller nozzles or smaller layer heights.