Double-wall, vacuum insulated, 18/8 stainless steel, copper lining and powder coated. Copper-lining keeps drinks cold for up to 24 hours and keeps drinks hot for up to 12 hours. Holds 14 ounces. Comes with a clear press on lid. Our eco-friendly bottles are free of single use plastics: We have now eliminated all single use plastic packaging materials on our powder coated reusable bottles.