Medela Breastmilk Collection Bottle Set - 5 oz - 6 Pk Medela Breastmilk Bottles are made from safe, BPA-free polypropylene, designed to retain breastmilk"s beneficial properties. Compatible with all Medela breastpumps, so you can pump, store and feed with one container. Features:Extra bottles are compatible with all Medela Breast pumps, as well as CalmaSafe, BPA-free bottles are designed to retain breastmilk"s beneficial propertiesIdeal for safe storage of breastmilk in refrigerator or freezerMeasure the exact amount of milk you"re pumping with the colorful ounce and millimeter markersScrew on lids for leak-proof storage, travel and freezingTravel cap keeps nipple cleanDishwasher & microwave safe