6" to 4" Duct Reducer

6" to 4" Duct inline Fan Reducer UPGRADED VERSION 2 After seeing a few basic reducers and finding parts I liked and didn't while not finding what I truly wanted. So….. I designed my own from scratch in Fusion. Then my first version wasn't quite right. This is designed to fit the AC Infinity Cloudline Pro 6" However I'm sure that there are many different brands that this will fit. Some 3rd part inline fans may need fine tuning tho. Talking about different Brands, I switched from an old 4" flexible duct to a new 4" Vinyl / Aluminum duct off of amazon and they were significantly different. I will post two versions, the threaded for the wire wound ducts, Along with a smooth connector for metal ducting with grove for a clamp <img src="https://makerworld.bblmw.com/makerworld/model/DSM00000001730631/design/2025-09-26_20382139