Ratchet, adjustable temples, flexible nose, MMT Economical lens replacement system. Lifetime frame guarantee 3/4 frame, sleek and built for high performance Uvex Genesis is engineered to deliver on the best all-day comfort, protection and style. It's built with MMT-MULTI MATERIAL TECHNOLOGY for comfort, and protects in a very wide assortment of lens tints. Uvex Genesis has an easy and economical lens replacement system. Frames have a lifetime guarantee. Made in the USA.