The Bebek Collection offers a wide base nipple for easier latch and transition. The silicone Proflow nipple rapidly vents, releasing air bubbles into the bottle, not baby's tummy, significantly reducing gas, colic and fussiness. Bebek nipples are expertly designed not to leak and to be used on all 5 ounce and 8 ounce Bebek bottles. The simple, one piece nipple and vent means no extra parts to clean or lose. Medium Flow nipples are designed for babies 3-6 months. Enjoy the bonding time that feeding provides.