I watched somebody trying to scratch through one of these with a key and was impressed at the result. Bought it at carphone warehouse and had them fit it. By the end of the day it had slipped and so they removed it and applied a fresh front and back. A couple of weeks later and I dropped back in complaining that it still wasn't sticking and they applied a fresh one again. Now a couple of weeks on and the back has slipped a couple of mm again - which is enough to have the film overrun the edge of the phone and from there it's only a day or two before the edge gets caught on something and the whole film gets pulled off. Awful product.