Nurser with slow flow nipple. For 0-3+ months. The Playtex Drop-Ins System is designed to help baby switch between breast and bottle. Patented NaturaLatch Nipple: Clinically shown to mimic babys latch-on like the breast. Slow-flow nipple designed to replicate the natural flow of the breast, so baby takes in the right amount. Compatible with the Playtex Nursing Necessities breast pumps. Just pump, store, and feed using the One Step breast milk storage kit (sold separately). Easy to store and freeze directly in the liner. Playtex Drop-Ins disposable liners are: Pre-sterilized for a clean bottle any time. 100% leak-proof guarantee. Pre-formed for easy one-handed assembly and clean-up. Bisphenol-A free (BPA-free) and phthalate-free. Two recent clinical studies confirm that the Playtex Drop-Ins System provides significant colic reduction and mimics the natural feeding patterns of breastfeeding: Clinically shown reduces gas and colic: In a clinical study, 8 out of 10 mothers indicated that their babies showed fewer signs of gas, colic and other feeding discomforts. Clinically shown to support babys own natural feeding pattern and support breastfeeding: Baby sucks and swallows in a coordinated rhythm that is similar to how they feed from the breast. Baby breathes more naturally. Baby can control the flow of milk, so he/she takes in just the right amount.