Material: silicone + PP. Color: blue. Size: 350ml: folded size: 13.2*3*9.8cm, unfolded size: 13.2*6*9.8cm. 500ml: folded size: 16.5*3*10.8cm, unfolded size: 16.5*10.8*6.5cm. 800ml: folded size: 18.5*12.2*3.2cm, unfolded size: 18.5*12.2*7cm. 1200ml: folded size: 21.8*13.8*3.2cm, unfolded size: 21.8*13.8*7cm. 4 * foldable lunch box. Material safety: The container is made of food-grade PP and silicone: non-toxic, odorless, environmentally friendly and BPA-free. The inner super smooth surface avoids oil stains and is very easy to clean. Ingenious design: lid with four-way closure, leak-proof silicone sealing ring. A small valve on the top of each container is used to release water vapor. Allows for easy and compact storage, easily folded to 1/3 the original size, saving you more than 60% space. Safe to Use: Used in microwave ovens, dishwashers and refrigerators. When heating in a microwave oven and using a heat-up time of no more than 5 minutes, open the outlet valve. IDEAL FOOD STORAGE: Perfect food storage. Easy to assemble and carry, it is the best lunch companion for children, an ideal choice for adults to develop healthy eating habits, and an ideal choice for gifts.