Product review (5 stars): Excellent high quality well made and designed roof vent cap
Excellent high quality well made and designed roof vent cap.  Used these to vent two Panasonic bathroom ventilation fans to the roof.  The Broan-Nutone duct collars (purchased separately and also reviewed) fit perfectly.  The similar roof caps I saw stocked at the local BORGs were cheap, flimsy, thin sheet metal pieces of crap.  I'm glad I took a risk and bought these instead.