He has to ask a rep if 3" will work...yikes! Seeing it comes with a 4" take off.Yeah I kick some tires Saturday, just went to one shop, They had the Harmon insert on display.Very nice stove. I didn't get to here it run 80 degrees out, They had an m55 but not insert. Store guy said they are both good which I know, parts have been more of an issue for m55. He said he could do 10% off on the accent insert which came up to $3500 I think the m55 insert was around the same. He said the 1200i was a good stove also $2600 for that. He kinda was saying accent was the way to go. Right now I'm kinda leaning that way. Would like to here them run. He said it would probably be all right to hook up to my 3" exhaust because my house is just one story but would make sure with rep.