Combining two innovative materials, this stainless steel lunch box set serves up hot and cold lunches. Features a stainless steel base and a premium silicone food compartment that can go from refrigerator or freezer to microwave and oven. For safety and comfort, there are soft touch silicone clips for easy opening and closing. Make sure to wash and dry your lunch box set before first use. Stainless lunch box base is oven-safe, but not microwave safe. Leak-proof. Do not use bleach, cleaners containing chlorine.abrasive cleaners or scrubbers on any part of the box as they may dull the finish. To ensure the box is sealed properly, check that the top edges of the base and silicone seal on the lid are clean and dry. Firmly push the lid down on all sides so there are no gaps then close the clips. Measures 7.5 x 4.75 x 2.25 in.