Black, Vacuum insulation technology with copper-plated double walls. Keeps the temperature, taste and nutritional value of your drink. Water stays ice cold for up to 15 hours and hot drinks stay warm for up to 6 hours. With an unbreakable stainless steel outer casing and an 18/8 interior, this thermos flask has a long shelf life. It has a stress-free anti-drip lid, with a leak-proof silicone seal.