The tempered glass by Idol 1991 is a hardened glass, specially designed to cover and protect your phone's screen from scratches and other damage. It does not affect the screen's functionality. In case of a phone drop, it does not guarantee that the screen will not break along with it, however, it is an additional protection. Its special processing makes the phone screen visible only from the front, preventing visibility from any angle. This protection is useful if you often travel by public transport and do not want those around you to look at your screen. On the contrary, it is not suitable for gaming or watching videos, as it darkens the screen. It is compatible with Galaxy S21 Ultra 5G.