iPhone 4/4S Screen Protector Premium Tempered Glass is made to protect the LCD from damage and scratches with specially processed glass that has been reinforced to increase shock absorbency.The entire surface of the glass is transparent and the back side is covered with a strong silicon adhesive for easy installation. When installed， there are no gaps between the LCD and the glass which means the touch screen's sensitivity is unaffected. 

The surface of the tempered glass has a hardness of 8-9H and 0.4mm thick， three times stronger than a regular screen protector film. Even objects such as knives and keys will not scratch the tempered glass.