Vacuum seal, leaf-proof design is ideal for sous vide cooking and can be used to store liquids as well as solids. Easy to read measurements make portion control simple for soups, sauces, liquids, and much more. Airtight seal helps to preserve the food inside and can be used to protect items from external water damage. Made from food grade silicone which is free from harmful chemicals. Heat resistant to temperatures up to 480 degrees. Dishwasher safe. Set of four.