Pumping breastmilk is a vital function for new mothers. Keeping the breastmilk safe and ready to store for future use helps to keep your baby healthy. This is why we has created these double-zipper and hygienically sealed breastmilk ready to use storage bags. The Medela Breast Milk Storage Bags have been hygienically pre-sealed with durable material and double-zipper protection to prevent leaking. These bags safely store breastmilk in the freezer, fridge, or when traveling. These ready to use breastmilk storage bags are constructed from a durable, double-layer material with a built-in double zipper seal to keep your breastmilk safely stored in the fridge or freezer.The breastmilk storage bags have been designed to be self-standing and come with a large write-on area. This allows you to document the date and other vital information for safer storage and use. Also, the UK Baby Breast Milk large 6-ounce Storage Bags have been designed to lay flat for space-saving storage. This unique feature allows quick thawing of frozen milk when your baby is hungry.