I used 6-inch sections of Dura-Spike on top of my downspout elbows where they exit the gutter and curve down into the downspout. This prevents birds from building a nest and creating a nasty poopy mess all over the house. There are plenty of trees around my property where the birds are welcome to nest. Just not on my house please. You will need a good pair of tin snips to cut it. Use stainless steel sheet metal screws when installing. This product is durable and easy to install. It should last forever. I highly recommend it.