What it is: This teat is suitable for a premature to low-birth-weight baby who is still learning suckling and swallowing, or has other physical challenges.What it does: The elongated teat closely mimics a mother's lactating breast, while the off-center teat design promotes upright feeding-similar to a position in which babies are nursed-to reduce the risk of milk back-flow that can result in mid-ear complications and colic. The built-in anticolic air vent reduces unwanted air intake and prevents bubbling of milk, saving nutrients from oxidation. How to use: Face anticolic vent toward you and line up with the Hegen logo in collar. Place the collar over the nipple and pull nipple upward through the collar to secure in place. The nipple will fit snugly into the collar. Pack of six BPA-free; BPS-free Silicone Hand wash Imported