These bags are great for freezing and thawing human milk. For the nanny or communities, etiquette is very convenient with the ability to put the baby's name (as well as the capacity and date the bag). Defrosting is done either in the refrigerator or quickly in a cup of hot water. I have not had any leakage problem, zip working fine. Once removed and the air bag closed while holding flat in a box in the freezer.
Warning, do not rely on the capacity of the bag. It is very flexible, the capacity is affected by whether the bag is more or less flattened. Therefore rely on the capacity of the bottle of breast milk. The opening is quite high, I happened to pour some milk on the zip pouring the milk in the bag. These bags are not made to fit the pump.
