The tempered glass is a hardened glass, specially made to cover and protect the screen of your mobile phone from scratches and other damages. It does not affect the functionality of the screen. In case of a drop, it does not guarantee that the screen will not break along with it, however, it provides an additional protection. It is 9D, which means it has undergone special processing to acquire curved edges that cover the entire surface of the mobile phone screen. This way, it is not apparent that the screen has protection, but the curved edges are also protected. It is compatible with Galaxy A12.