Medela breast milk storage bottles are seamlessly compatible with all Medela breast pumps, so you can use it as your go-to breast milk storage and feeding container. Colorful ounce and millimeter markers ensure that measuring milk is easy, so you always know how much you’ve pumped and how much your baby is eating. Accompanying screw-on lid and travel cap helps secure bottle contents when on the go and keeps nipple protected from outside elements. Medela’s breastfeeding bottles are designed to help promote leakproof storage and freezing.  Nipple Level 2 - Medium Flow