Do you know what is tr90 glasses?do you know spring hinge?TR90, also known as plastic titanium, is a kind of polymer material with memory. It is the most popular ultra light eyewear frame material in the world. It has the characteristics of super toughness, impact resistance and wear resistance and low friction coefficient. It can effectively prevent the damage to eyes and face caused by frame fracture and friction in motion.
![Basics in Behavior [RED]](https://i.ytimg.com/vi/LE2g9pnv0w0/mqdefault.jpg)
