The Sapora 12 oz Stainless Steel Mug with Cork Base is constructed of 18/8 stainless steel with a powder-coated matte finish. The double-wall, vacuum-insulated mug has a decorative cork base, that is 90% cork & 10% cork glue, and molded matching metal handle. Clear plastic push-on lid with sip-thru opening and copper-lined to keep beverage hot for up to 6 hours and cold up to for 8 hours. Recommend hand wash only. BPA Free & FDA certified.