The bags can be piled on top of one another and are perfect for being stored in the fridge or in the freezer. The great thing about those bags is that each of the 25 sterilised bags holds 180ml of milk and is ready to be used whenever you need to – even if you are in a hurry. Annoying cleaning before or after using the bags can be missed out. The double safety fastening keeps the milk safely inside the bag which is made of BPA-free synthetic material.