The foam material is somewhat noisy when opening and closing, at least on a marble floor, and it can tear if it gets caught under furniture, etc. Other than that, it is cheap and seems to do its job quite well as an insulator. It fits tightly on my old wooden door, so it would hardly fit on a thicker security door.

Very good purchase. I am fully satisfied. It fits well. As a single note, I would say, be careful with the thickness of the door you want to apply it to. If it is too wide, you might not be able to install it.