125mm to 2x 79mm duct adaptor Air duct

thingiverse

Made this simple adapter for a 125mm Exhaust fan, so you can use an approx. 80mm hole drill (if you drill through a wall), instead of a big one 125mm (only had the small one available, so I drilled 2 holes for use with this adaptor). The area of the small 79mm tubes is a bit less than the 125mm, but still, almost the same air capacity. If you try to buy an adapter online, you will only find those universal adaptors and only 1x1 125 to 80 , which is insufficient if you need the airflow not to change that much.