Material : Stainless Steel & Plastic KEEP FOOD FRESH -- Bento Boxes keeps meals and snacks fresh and mess-free during transport, prevent food from mixing together, separating vegetables, fruits and snacks to maintain the original taste of the food PREMIUM USE -- Microwavable, Freezer and Dishwasher Safe，Use for School, Work, and Travel. Note also that thanks to their compartments, space-saving design, these bento lunch boxes fit into one another for easy and convenient storage