Uniquely designed spool with polymer membrane allows to develop modified atmosphere within the air tight bag and box and increases shelf life of fresh produce without use of machine. Modified atmosphere packaging spool has four different parts. 1. Outer body. 2. Inner ring. 3. Mesh. 4. Polymer membrane. It is applicable on mouth of bag to close it properly and exchange of oxygen and carbon-di-oxide through the polymer membrane. Spool is reusable.