Serengeti Lenwood Sunglasses pair a large rectangular acetate frame with Serengeti’s ultra-light mineral lens technology for adaptable, high-contrast vision in changing light conditions. Key attributes: Gray | Transparent | Acetate | Photochromic (light-adapting) lens | Polarized lens | Spectral Control® technology | Ultra-light mineral lens | Prescription lenses available | Anti-reflective coating on lens back side | Chemically tempered for scratch and impact resistance | Large rectangular frame | Shiny crystal finish | Italian-made acetate construction | Dimensions & fit: Lens width 57 mm | Bridge 18 mm | Temple length 155 mm | Extra large fit | Base curve 6 | Composition & care: Frame: Cellulose propionate acetate | Lens: Ultra-light mineral glass (borosilicate) | Blow loose particles off lenses, rinse with lukewarm water and clean with a non-abrasive soap. Dry and polish with an optical lens cloth. Do not use solvents or abrasive cleaners. Store in the supplied case and avoid leaving in extreme heat or cold. Put on and remove by holding both frame arms.