Abuff 4 inch Duct Connector, 2 Pack Plastic Straight Pipe Flanges, Ventilation Ducting Connector for Heating Cooling Ventilation System

Built a box and made a cutout for this for roof vent exhaust fan with 4 inch exhaust hose. Works perfectly for the job I used it for

They work fantastically. I used one to attach a 4" hose to my laser enclosure which came with a 3" port. Now I get better flow and this truly takes care of the miniscule amount of fumes that were escaping previously.

I use these for my printing enclosure to vent out fumes. It’s very sturdy and secure, holds the vent tube well, and doesn’t come loose.

Works great using them on a couple vevor diesel heaters. Makes it easy to hook up 4” ducting to both inlet and outlets of the heaters.

Used on the side of a box that houses my laser engraver.

Works as intended.

I use these thur a sheetrock ceiling to exhaust my electric dryer thur my attic out my exterior wall of my home

Thin, cheap and not at a ll like photo shows. Has 4 holes not 6 and is very thin on outter mounting ring not at thick as shown in photos. It is actually 3.8 inches OD not 3.9 like photos and description states. In metric it is also not 100mm but 97mm OD. Specs says 6 inch and yet it measures 5.45 inches on outer flange edge or 139mm not 150mm like advertised. I am probably going to end up returning it, but it can be a pain to return products and then I have to find and buy some other cheap brand to finish my project.