A stainless steel vacuum flask (thermos flask) is a durable, insulated container made from food-grade stainless steel and designed to maintain the temperature of liquids for extended periods. Its double-wall vacuum insulation minimizes heat transfer, keeping beverages hot or cold for hours. The flask is rust-resistant, leak-proof, easy to clean, and suitable for carrying water, coffee, tea, soups, and other drinks for use at home, work, travel, school, or outdoor activities.