VALUE SET CONTAIN DIFFERENT SIZE - Set of 4 silicone collapsible containers fit for different needs and different people. You can use the small one (350 ml) for your daily healthy snack, the medium one (500 ml) for your kid's meal, the large one (800 ml), and the extra-large one (1200 ml) for yourself or your significant others. SAFE MATERIAL WITH PREMIUM QUALITY - The food storage box is made by food grade BPA free silicone that is non-toxic, tasteless, odorless, non-stick, and easy to clean. The material has a temperature tolerance range from -20C~220C.Open the vent valve when using the microwave oven PRACTICAL DESIGN FOR DAILY NEEDS - The collapsible thin bin design shrinks down the size of more than 50% when the meal prep box is not in use. They are foldable stackable and the space-saving feature can help you to save your kitchen cabinet space and keeps your cabinet in organize. The airtight lids keep your food is fresh and the air vent is great for convenient microwave heating. ALWAYS READY FOR YOUR LEFTOVER - Comparing with old fashion heavy glass containers, those space savers are light weighted and easy to carry. You can always bring one of them with you, and start to protect our earth by using your reusable leftover container instead of a one-time plastic bento box.