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. The special processing makes the screen of the mobile visible only from the front, obstructing vision from any angle. This protection is useful if you frequently travel on public transportation and do not want those around you to look at your screen. However, it is not suitable for gaming or video watching as it darkens the screen. It is compatible with Galaxy A04s.