1) imported material from Italy. Longer time won't be yellow. 2) More easy for tinted the color fur sunglass. 3) Diameters: 1) imported material from Italy. Longer time won't be yellow.2) More easy for tinted the color fur sunglass.3) Diameters: 50mm,55mm, 60mm, 65mm, 70mm,75mm4) Uncoated lens, hard coated and Multi-coating,HCT,Super hard5) progressive,flat top/round top bifocal, Tinted lens, ...