Fangrui Product Details Superior Temperature Insulation - The Vacuum Insulation And Insulated Bag Provide Up To 4 Full Hours Of Warm Retention With 42 Degree ; Nearly Twice As Long As Others. No More Cold Lunch. No More Microwave. The Vacuum Insulation Provides The Right Temperature To Keep Food Stay Warm And Healthy. Convenient To Enjoy Tasty Homemade Food At School Or At Work. Premium Material - Interior And Exterior Are Made From High-quality Food-grade Stainless Steel Ss304 Which Rust And Is Naturally . Does Not Retain Flavors Or Scents, So You Can Use It Over Over Again. The Handle And Divider Are Made From Food-grade Plastic. Leak Spill Proof - Between Each 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 Leaks And Spills. And Please Don Lose The Silicone Valve On The Bottom Of Each Layer Which Keep It Leakproof. Lunch Bag - Made Of Felt Fabric And Food-grade Aluminum Foil-lined Interior, It Can Not Only