Luigi Bormioli Set of 4 Allegro 13.5 Ounce Double Old-Fashioned Glasses,Luigi Bormioli,09479/02" /> 13-3/4-ounce Doulbe Old Fashion, Set of 4 Luigi Bormiolis proprietary material called SON.hyx allows the glasses to be extremely break resistant and transparent. 25 Year Guarantee! The guarantee covers chipping on the rim or foot as well as any discoloration or cloudiness resulting from dishwashing. Innovative glassmaking techniques produce perfectly smooth rims and edges 25 year guarantee covers rim and foot chipping as well as discoloration