Asahi Kasei Bento Box Set - 4-Piece Rectangular Food Storage Containers (2x2) 20.1oz/510ml - Microwave & Dishwasher Safe Lunch Boxes for Office, School & Meal Prep

The main unit and lid are heat-resistant up to 284°F (140°C), and the cold temperature is -4°F (-20°C), and the lid can be heated by microwave. Of course the same size, you can stack them together and store them in different sizes Press the middle part of the lid to snap shut and seal tightly. There are markings on the side of the container so you can check the amount of contents.