Serengeti Sunglasses Cetera 7340 Dark Tortoise Brown Drivers Polarized Photochromic Grey to Clear Gradient Brown Mirror AirEvac ventilation and three layer DriWix TEDB RX TB9195 608#HH AirEvac ventilation and three layer DriWix face foam work together to maintain a clear non slip grips Serengeti Sunglasses Cetera 7340 Dark Tortoise Brown Drivers Polarized Photochromic are a wrap around sporty sunglass with a lightweight durable construction and this model has the standard Drivers lens which is the cornerstone of the Serengeti lenses range with the superb optical performance and Spectral Control given by the superb manufacturing technology used by Serengeti to make these amazing photochromic lenses