IRIS OHYAMA Heat-Resistant Glass Containers 8-Piece Set TGS-8S Clear Black Stored unopened since purchase. (Only the lid of the box was opened for the photo.) Basic Specifications Set Contents: Square SS size, S size, M size, L size, 2 of each Body: Borosilicate glass, Lid: Polycarbonate, Packing: Silicone rubber These are heat-resistant glass containers that can be used in microwave ovens and ovens. They are useful for storing food that has been prepared in advance, serving directly on the table instead of plates, and for making sweets, among other uses. The lids have packing for airtight sealing, making it difficult for liquids to spill. They are resistant to color and odor transfer, so you can put in dishes with strong acids, salt, or curries. They can be stacked for neat storage in the refrigerator. The clear containers make it easy to see the contents. This set is easy to use for both cooking and storage. They can be stacked for compact storage. They are easy to clean and wash, as oil stains come off easily. Dishwasher safe. (※The lids cannot be used in microwave ovens, ovens, or dishwashers.)