Less air, less gas for healthy feeding; Eases switching between breast and bottle. NaturaLatch Nipple clinically proven to support breastfeeding. Playtex NaturaLatch Silicon Nipple: NaturaLatch Slow Flow is the only nipple clinically proven to support breastfeeding; Baby latches on in a similar way as breastfeeding, for a more natural feeding. Raised textured area encourages proper latch-on. For the best performance use only drop-ins pre-formed soft bottle liners with Playtex Nurser. 1 Nurser with Slow Flow Nipple. Colors may vary; See side window for color. Available in 5 colors.