PC lens has a very strong toughness, won't broken, also known as a safety glasses; Gravity is only 2 grams per cubic centimeter, is the lightest material for lens; UV400 fully resist ultraviolet; Extremely suitable for travel; Frame is made of TR90 (plastic titanium), which is currently the most popular ultra-light frame material; Super tough, anti-shock and abrasion resistant, low coefficient of friction; Effectively prevents eyes and face from hurt by broken frame and friction during movement; Anti-deformation, high temperature resistant, difficult to get melt or burning; No release of chemical residue, meeting European requirement to food-grade material