I bought this for my brother who was a shift work and can not lunch or home, or in a canteen and even less in the restaurant. You have to heat water in a kettle and fill the thermos with boiling water and leave for ten minutes. During this time you made your dish warm in the microwave, then you put it in the thermos. This thermos keeps hot foods 4-5 hours without difficulty. My brother is happy to eat hot now. The product is perfect for its size it does not take up much space and can easily be placed in a ^^ satchel or briefcase .. I recommend this product.