This lunch box is made of 304 stainless steel and food grade PP material, BPA-free, healthy and durable. We use thicker materials that are not easy to break. The top and bottom are very strong. This Stainless Steel tray is removable, can be cleaned up easily in the dishwasher. The plastic bottom box is freezer safe, BPA free, another useful function is you can pour in some hot water before you eat to heat the food. The lid fits tightly to the stainless steel food tray, so food does not run from one compartment to another, preventing food from mixing. With a 100% leak-proof bowl, you can store liquids such as sauces or yogurt in it. 4 compartments Features , convenient to store variety food with divided lunch box design, portioned perfectly for adult/ child's appetite, durable and easy to-go.