This superior insulated double walled vacuum flask is designed for maximum temperature retention. It Keeps hot liquids warm for uptown 4 hours and cold liquids cold for up to 5 hrs. The wide mouth makes it easy to fill, serve from and clean. It has heat resistant handle for easy carrying and easy storage. Please Note: Before Putting Hot Tea or Milk inside the flask, we have to wash it with hot water for temperature maintain. After temperature maintains, we can put any liquid in flask & it will not have any effect on the product.