I have an 18' garage door. This just barely fit the width of the opening. If I would have mounted this to the outside trim of my garage it would have been too short as well. I ended up running the velcro along the bottom edge of the garage door itself. I release the door from the opener and let the door hang about 6". the screen itself does what it is supposed to (keep bugs out) and works well. the only drawback to my install is that I have to take it down before closing the garage door. Not really a big deal as it is pretty easy to put up/take down.