Sherr 500 Pcs Breastmilk Storage Bags are designed to store and protect breast milk for new mothers. These bags have a double sealed side seam to prevent air from entering and leaking, ensuring the milk is safely stored in the refrigerator or while traveling. The double opening design allows for easy pouring and preservation, while the bottom support design keeps the bag upright, saving space. The bags are pre-sealed for immediate use, made from fine PE material, and include a writing area for easy recording of storage time and capacity.