Ray-Ban RB3357 - GUNMETAL Frame CRYSTAL GREEN Lenses 63mm Non-Polarized Acetate and Metal Frame. Acetate is a plant-based plastic known for being lightweight, yet durable. Every model in the Ray-Ban collection is the product of meticulous, original styling that translates the best of the latest fashion trends into an ever-contemporary look for millions of Ray-Ban wearers around the world. Ray-Ban sizes refer to the width of one lens in millimeters. Ray-Ban products sold by authorized sellers, like Amazon.com, are eligible for all manufacturer warranties and guarantees. Protective case included, cases come in a variety of colors. Lenses are prescription-ready (Rx-able). Ray-Ban products include an etched "RB" on the left lens. The RB is not a scratch or defect. The shape and curvature of these sunglasses may need adjustments. Adjustments should only be made by a professional. Made in Italy or China.