Breast milk has great benefits to your baby's healthy development and so these baby bottles are designed exclusively to store, protect and maintain breast milk's complex life-enhancing beneficial properties through all the stages of refrigeration, freezing and warming within an optimal temperature range of -2C and +37C. Pump, store, and feed from the same bottle to maximize available expressed breastmilk for baby. You can also easily track your baby consumes at each feeding. Set of three. BPA-free, food-grade bottle and lid. Reduces preparation time. Compatible with all Medela Breastpumps and the Calma feeding system. Non-reactive material ensures breast milk protection. Accurate volumetric graduation lines. Model number: 27232.Polypropylene. Hand wash. Made in USA. SPECIFICATIONS.