Tempered glass is a hardened glass, specially designed to cover and protect your mobile phone screen from scratches and other damages. 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, but it provides additional protection. Its special processing makes the phone screen visible only from the front, blocking the view from any angle. This protection is useful if you frequently use public transportation 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 the Redmi Note 9S / 9 Pro / 9 Pro Max.