Always Fresh containers locks in freshness so food lasts up to 50 days longer than ordinary plastic storage containers. Save money food stays fresher longer, so you throw away less. Made with nanotechnology, containers include silver nanoparticles naturally antibacterial and help prevent the growth of mold and fungus. Great for fruits, vegetables, herbs, cheeses, soups, sauces, meats and more. Keeps bread soft and cookies and crackers crisp. Ten piece set pluslids. Plastic.