Premium Material - Interior is made from high quality food-grade stainless steel SS304 which will never rust and is naturally BPA-free. Does not retain flavors or scents, so you can use it over & over again. The exterior and dividers are made from food-grade safe plastic. Versatile Design - It can be used for hot food such as soup, fried rice, etc which will keep warm for 1-2 hours or cold food, such as salad, pasta, fruit, etc. You can use 1 layer, 2 layers or all the 3 layers for different food combinations.(NOTE: The insulation time will vary depending on the environment.) Leak & Spill Proof - Between each stackable insulated compartment are heavy-duty silicone seals to lock in freshness, leaks and odors. Please be aware that the coupling between layers is tight to prevent leak and spill. After using it for a couple of times, it will become smooth. All Accessories Included – It includes an upgraded lunch bag which is more durable and easy to clean and 3 extra silicone seals so you don’t need to worry about losing them. Ideal for Portion Control – Wrap it with ribbons, give it to someone you love so they can enjoy home made delicacy for a healthier eating style!