Medela Calma 5oz Bottle with 2 Lids, Yellow and Clear with Measurements, 68021 features a no-drip nipple design and is compatible with all Medela containers. Calma bottles only flow if your baby works to create the suction to remove the milk, helping your child transition smoothly back and forth between bottle and breast. This Medela Calma 5 oz. Feeding Set includes (1) Calma nipple, (2) Multi-lids, and (1) 5 oz/150ml bottle. All parts included are safe for the top rack of the dishwasher. Made without BPA.