Vented no drip nipple.
Medela Calma Bottle Nipple - Calma by Medela has a patented air-vent system that allows milk to flow only when baby creates suction. It is suitable for all ages, eliminates the need for flow rate adjustments, and fits the Medela collection and storage bottles. Calma can be cleaned, stored, and transported, and is made without BPA. What’s Included: (1) Calma Nipple; (1) Cap; (1) Lid.