iPhone 4S Tempered Glass Screen Protector, iSee Case (TM) Pro-Glas Premium 0.4 mm Shatterproof Ultra Clear Tempered Glass Glass Screen Protector for Apple iPhone 4S iPhone 4 (4S-Glass) to absorb shocks, and protects the LCD from scratches and physical damage Crystal Clear transparent thickness of 0.4mm and a tolerance 0.02mm (positive and negative) The screen protector was put through several tests in the laboratory, and it came through every time creating new standards for ultra high performance. it can be installed easily and there are no gaps between the LCD and the screen protector so your touch screen sensitivity stays unaffected. It is laced with a strong adhesive that makes every inch of the protector cling to your screen. hardness of 9H. You can test it by trying to scratch it with sharp metal objects, as we do in our labs for quality assurance. You will find that not even sharp knives can scratch it, let alone car keys.