Product review (1 stars): Bad design for sidewind with rain
After receiving this product, I was disappointed to find that there is no inner flap over the downpipe. So if you have strong sidewinds with rain like I do at my house, rain that drives up through the gap under the round cover can go straight down the vent tube into your house.

Unfortunately I missed the one month cutoff to return this by a few days, so I am stuck with a useless vent closure. I wish the design was more clear in the Amazon product description...I hope this review helps others in their decision.