NanoNine Micro Safe Steel Stainless Steel Single wall lunch box is designed to keep warm food fresh and retain aroma & taste longer. | FOOD GRADE & BPA FREE LID: The Lid is made of Food Grade and BPA free plastic material. | Microwave Safe Containers : Top three round containers are Microwave Safe and to be used without Lid | AIR TIGHT: The Air Tight lid of the lunch box keeps food fresh for hours. | HIGH QUALITY STAINLESS STEEL BODY: Lunch Pack is made with Rust Free and Corrosion Resistant Stainless Steel.