Lansinoh breastmilk storage bottles have been specifically designed for the safe storage of breast milk lansinoh breastmilk storage bottles have wide neck design that makes them compatible with all of the lansinoh range of pumps so you can pump stratight into the storage container pack of 4 160ml storage bottles for expressed breastmilk the bottles are made from polypropolene a medical grade plastic preferred for the storage of expressed breastmilk dishwasher and freezer safe