18/8 Stainless Steel, .7Mm Thickness, Stackable Tray With Molded-In Solid Silcone Rubber Surface To Prevent Slipping. 14″ X 11.5″ X.75″ Dishwasher Safe, But Hand Wash Recommended For Longer Life. Product Manufactured Before May 2012: Solid Rubber Surface Was Made With Tpr (Thermoplastic Rubber,A Plastic/Rubber Blend).Product Manufactured Starting Late 2014- Po Mn.10073 Switch To Rubber Nbr.