I bought this for a crank out window that has never had a screen. The instruction wording was confusing but the basic idea is simple. the white corner pieces will not stay on for me. There are a few places where the magnetic strip buckles and then there are gaps where insects enter. They could improve it and I would be willing to pay more for a better magnetic screen. It's not terrible and does what it should for the most part. I do appreciate being able to open a window with some sort of bug barrier, so, thank you.