Product review (4 stars): 6" Vent for 30" under cabinet hood.
Looks great and is fairly easy to install in spite of the location of the pigtail connection which was a bit too far to the right rear and we had to notch the cabinet to get the electric cable through. What the product description lacks is the size of the exhaust vent.  It is 6" round. There's also an adapter for a 3" x 8" vent.  I sent an email to the vendor requesting the diameter of the vent but never received a reply and had to wait for the appliance to show so that the proper vent pipe could be installed and dry-walled over.