[Keep Food Warm] The middle layer of this bento box is made of high-density insulating PU foam, which is more insulating than the vacuum layer. It can keep food warm/refrigerated for up to 4 hours at room temperature. Before use, it is recommended to preheat the bento box by wetting the inside and outside with hot water. After the food is cooked, it is recommended to put it into the bento box immediately before putting it into the insulated bag. [Widely Used] This kids lunch box is convenient for you to enjoy delicious homemade food at school at work or on the go. Great for storing soups, fried rice, pasta, or other hot foods, and can also be used to store cold foods such as salads and fruits. Perfect for school, working adults, exercise, camping, and traveling. It is a good choice as a gift for your loved ones and family. [Individual Food Container] These lunch box containers can be used to store different food items such as hot food, pasta, soups, salads, fruits, and snacks separately according to your preference and needs. Avoid mixing food to ensure the original flavor of food. [Leakproof Design] This bento lunch box is equipped with a silicone seal that locks in freshness, leaks, and odors. The coupling between layers is tight to prevent leaks and spills. And please do not lose the silicone valve at the bottom of each layer to keep it leak-proof. [Premium Material] This bento box adult is made of quality food grade 304 stainless steel inside and out, not easy to rust, and naturally BPA free. does not retain taste or odor, so you can use it again and again. The handle and divider are made of food-grade plastic and reusable.