301 is the new Photochromic Sunsensor Sport Sunglasses by Bertoni Italy made in shatterproof Nylon Mesh. You can choose between 2 different photochromic lenses. A traditional photochromic lens from clear transparent to grey and a photochromic polarizing lens that combines the versatility of the photochromic effect with the antireflection action of the polarized effect. Both photocromic and photochromic polarized lens darken in 8 seconds and lighten automatically depending on the lights exposure. The material of the frame is shatterproof Nylon-Mesh. The bending of the front frame makes F301 windproof, comfortable ans specially indicated for Cycling, Running, Golf, Fishing , etc. The nosepad is adjustable in order to offer a perfect fitting. Packing : cartoon, hard case and lifetime guarantee. Bertoni provides lifetime after sale service for all Bertoni goggles and sunglasses. Bertoni provides lifetime after sale service for all Bertoni goggles and sunglasses.