Product review (2 stars): Doesn't fit well
I bought this for my Broan 2800 series downdraft ventilation system but it doesn't fit. It is too loose. The square edge isn't quite square. When attached they are large spaces which prevents the device from being secured to the broan unit. You could put some flash-band between the to to fill the void but the surface where this is require is quite narrow an i believe it would not hold. Needless to say I returned it.
I must admit that I required one that connects to a 4" round duct instead of the 6" so this would have prove difficult at the other end of the of the connection as well but a reducer would have done the trick so I wasn't too bothered. Its a shame that the correct 3-1/4 x 10" side didn't fit either.