This is the latest from Dec 12. 5 stars.
This worked exactly as described. You simply slip it over the top of your vent, cut it to the right angle of your roof (I just used a regular hand saw), and then screw in the screws (included) to help secure it so it doesn’t blow off in a storm. It took about 30 minutes to install and I did it all by myself. Super easy and a great product!