Stylo Insulated Tuff Jugs (Milton)Insulated Steel wall flask is made up of a durable 18 8 stainless steel, built to withstand the demands of everyday use. Inner copper coating for better temperature retention. Insulated technology keeps beverages hot or cold for hours Top lid has a slot with a provision to keep sugar cubes, tea bags, medicines etc. Wide mouth for easy filling and easy cleaning, it is leak proof. Pre condition flask with hot water if using for HOT beverage and cold