4 inch Duct Exhaust Flange

Here is a 4" Duct flange to help connect 4" round duct work for exhausting what ever you need. I used mine to exhaust fumes from my K40 co2 laser.

I used 6-32 x 3/4" machine screws but I made the holes smaller so you can drill them out for larger screws or use smaller ones if that's what you have on hand.