That with the "highest degree of hardness" I can not confirm that. In normal use of the mobile phone, the film holds so 4 to 6 months and is then well zerrkratzt and worn must therefore up a new one.
The display, however, is perfectly protected. After 1.5 years, my display still looks like new. So far, no scratch is (2 of evil) came through the foil. It's worth the biannual exchange. I immediately ordered me some.