Product review (2 stars): Only Fits Rectangular Venting
I'm sure this is a fine range hood. The reason I don't like it is because the search picture showed this hood with a circular vent but, when I received it, I saw it was for a rectangular vent. Amazon was quick to take it back and replace it with Broan model 423001 which does accommodate my circular vent.

I hope this helps others not to make the same mistake as I made.