This 20 oz stainless steel tumbler features a double walled, 18/8 stainless steel construction, vacuum insulation, copper plated inner wall, acrylic top lid with sliding sipper. Comes in a variety of colors, all with matte finish. This thermos keeps drinks hot for up to 8 hours or cold for up to 16 hours and comes individually polybagged. Materials: 18/8 Stainless Steel (inside), Powder Coated (outside), Acrylic (lid)