Arnette AN4291 Cortex square frame is part of the Bio-Plastic collection of frames made of GRILAMID BTR 600 LS, an innovative material defined by international standards as “Biobased". 56% of its composition is derived from renewable sources (Castor oil), making it noteworthy for its reduced impact on the environment. Arnette products sold by authorized sellers, like Amazon.com, are eligible for all manufacturer warranties and guarantees. Visit the Arnette shop by clicking on the brand link above to shop the entire Arnette assortment.