1. Material safety: Containers are made of 100% food-safe PP and silicone, non-toxic, odor-repellent, environmentally friendly, BPA-free. Super smooth surface on the inside to avoid grease and very easy to clean. 2. Includes 4 containers: 13.2 x 3 x 9.8 cm (350 ml), 16.5 x 3 x 10.8 cm (500 ml), 18.5 x 12.2 x 3.2 cm (800 ml), 21.8 x 13.8 x 3.2 cm (1200 ml). 4 different sizes for a variety of situations such as picnics, travel, work, etc. 3. Ingenious design: Lid with 4-way click lock, leak-proof silicone sealing ring. Small valve on the top of each container for the release of water vapor. Allows for simple, compact storage, collapses to 1/3 of its original size for easy use, saving you more than 60% space. 4. Safe Use: Suitable for microwaves, dishwashers, and refrigerators. Applicable temperature range is -40°C ~ 120°C. Open the outlet valve if heating in the microwave and heating time does not exceed 5 minutes. 5. Ideal Food Storage: Perfect for food storage. Easy to assemble and carry, it is a great lunch companion for children and ideal for adults to develop healthy eating habits and makes a great gift.