Here is my concern. I think they are a great idea to use in practice for both the pilots and the judges, along with callers and coaches. I think I might make up the same for the Tailwinds field. Love the concept. What I disagree with is using them during the contest. I can see the box with the painted lines and the poles. I can make a good estimate of my distance and height. So can the judges. All is fine. Now if these are used in the contest you now have something the pilot cannot use but the judges can. But it is not in the rules.