There are two types of screen protectors. One is glass and the other is plastic. The quality of both is quite good. You can buy both together if you want. Using it will give you a premium feel. And it is a very important thing for the safety of your smart watch display.

A full coverage PMMA (Poly (methyl methacrylate)) screen protector is a type of protective film designed to cover the entire surface of a smart watch's screen. PMMA is a type of plastic that is often used as a substitute for glass due to its shatter-resistant and scratch-resistant properties.

A full coverage PMMA screen protector can help to protect your smart watch's screen from scratches, cracks, and other damage. It can also help to keep the screen clean and free of fingerprints and smudges.

When choosing a full coverage PMMA screen protector for your smart watch, make sure to select one that is specifically designed for your model of smart watch. This will ensure a proper fit and maximum protection for your device.