This kind of lunch box is different from ordinary plastic container. Our material is advanced plastic PP material + stainless steel container, which is 100% harmless to human body and environmentally friendly.The inner layer of the lunch box is EPS foam material, and the inner liner is brand new stainless steel material. With the function of heat preservation, it can be maintained for 3-5 hours.The lunch box is of high quality and has a long-lasting effect of heat preservation. The design of the lunch box pays more attention to fashion and convenience, which is very beautiful and lovely. It is a good helper for us to carry food in our daily life.