The problem arises then in "contact with the enemy". Phone and keychain landed one day in the same pocket. After about 5 minutes I had two significant cracks in the film, under the then air bubbles have formed, which no longer even let off. Since this incident, I make sure that the phone is always solo in his pocket. Since there with scratches or dents, no more problems, is also nothing there which could cause just such.
Therefore, I only 3 stars. The protection of the display has been operating, the "extreme robustness" but I miss.
