These oxygen absorbers protect your food for long-term storage. Simply drop a packet into the package before closing to eliminate oxygen, which helps preserve freshness, prevent mold and bacteria growth, and extend the shelf life. Each packet will remove oxygen from a 1-gallon bag and removes over 99.9% of oxygen from each sealed, airtight package. Great for freeze-dried, powered, and dehydrated foods, including jerky, crackers, and grains. Set of 50; these are packed in sets of 10. Once a set is opened, vacuum seal any extra absorbers (or store in airtight jar) to maintain effectiveness. Best if used within 2 years. These must be stored in an air-tight glass container; do not store them in a plastic bag.Specifications and Features: Packet contents: 70% iron, 10% diatomaceous earth (10%), 10% water, 5% activated carbon, 5% sodium chloride Each packet is 2" x 2 3/4" and contains .57 oz. Use one absorber per 1-gal. bag or 300 cc of foodstuffs Set of 50 (5 packs of 10) "Do not eat" is printed on each packet Vacuum-seal unused packets until ready to use Best if used within 2 years FDA approved and certified