Hi there and welcome!I'm planning to do the mailbox type mod and noticed everyone seems to use the semi-rigid ducting is 3", which is not available in New Zealand.
I can get 4"+ and 2" (the 2" is actually stainless exhaust hosing)
Which one would be better to get?
The only reason I necked mine down was to fit the 3 inch inlet on an MES 30 .Sounds like 4" is the way to go (allows more flow)
My smoker cabinet is custom built, so I got no feeder inlets etc