Made of food-grade PP plastic and stainless steel, the lunch box is totally nontoxic and healthy. It's high quality temperature resistant, non fragile material,safe and reliable. Using PTC constant temperature heating,the use of a more safe and heat insulation dual function. Unique heating design,the temperature is more uniform,the food is more soft. Easy to go out to bring food, vegetable,soup and other food. The heating lunch box is suitable for driver who has to drive on the road for a long time daily. It's really a good present for them. Don't hesitate to place the order. Switch on the power,the power indicator lights on indicating that the lunch box began to heat up.