"I installed three of he Avalon Critter Quitters® about three weeks ago. The installation was easy and I only needed to cut the base of one of the three Critter Quitters® that I purchased. The screws hold the Critter Quitters® tightly in place. and it was very easy to position it upright. A little of the history of my problem. While cleaning leaves off my roof, I was surprised about two months ago when I noticed that the lead-covered PVC vent pipes were being consumed (chewed) by squirrels. I never knew that this was a problem until I looked at nearby houses and saw that they too were severely damaged. It was easy to see that eventually the rain water entering the space between the lead pipe and the PVC would accumulate and cause wood rot in the roof. My roof is only 5 years old. :-( However, the fact that these "rats with furry tails" could consume such a large amount of lead was surprising. I quickly became better educated when I did a Google search and troubled to learn that this is a major problem. One option was to use copper piping to cover the PVC (instead of lead). The installed copper pipe didn't look very well in the photos. I suspect the replacement from lead to copper would be quite expensive. I then came across your website. Your Critter Quitters® is well designed and constructed. I especially like how the rain water coming into the top of the Critter Quitters® is directed back into the vent pipe and not into the space between the remaining lead pipe and the PCV. Let me end by again saying thank you for providing such a great and useful product. Its a big success. I don't typically write endorsements like this but your product is that good! When you start fully advertising the Critter Quitters® and the widespread problem that it fixes, you won't be able to keep it on the shelves!"