Built to provide technically advanced eye protection to enthusiasts of all sports and outdoor activities, Tifosi Radius FC sunglasses deliver great performance whether you're running a 10k, riding a century, or just heading out on town.. . . . . . . Grilamid TR 90 frame offers an extremely high alternative bending strength, low density, and high resistance to chemical and UV damage. High Speed Red Fototec photochromic lenses provide 35.3 13.5% L.T. light transmission, enhance contrast, and are perfect for mountain biking, hiking, or trail running. Fototec lenses transition in 10 seconds transition time is slower when inside your vehicle due to the UV protection in the windshield. Lenses are made of scratch resistant, shatterproof polycarbonate with embedded polarized material. Optically decentered lenses eliminate distortion and prevent distracting magnification. Lenses are vented for increased air circulation to prevent fogging and keep you cool. FC Full coverage lenses provide additional protection. Hydrophilic rubber nose pad and earpieces ensure a non slip fit. Adjustable temples and nose allow for customizable comfort. All Tifosi sunglasses provide 100% UVAUVB protection. Best fits small through large sized faces .