Insulated Lunch Box is made of PP plastic outer layer, with food-grade stainless steel inner layer, heat insulation and anti scalding. Single-layer, double-layer and triple-layer styles are available. With the lid on the top layer, and silicone sealing ring is embedded in the lid which can make it airtight. Note that open the sealing valve at the top before opening the cover, and this lunch box cannot be microwaved. With concealed handle design and safety locks on both sides, this lunch is easy carrying and suitable for office or outdoor. Imprint lunch box only can be hand washed.