NEW: Gen 2 nipples for our newly-updated Breastmilk Bottles and Sets! Gen 1 nipples are available for the original Breastmilk Bottles. Both versions will work with the Flexy Silicone Bottle. * Anti-Colic: Features an advanced 360° anti-colic system that relieves air pressure to prevent gas so baby is fed and happy. * 5 Different Flow Rates: Preemie, Slow Flow, Medium Flow, Fast Flow, and Y Cut. Good for every stage of development from preemie to infanthood. * Extra Soft & Familiar: Designed with a mom-like shape and natural feel that helps baby easily latch to the nipple. They help prevent nipple confusion and are perfect for babies transitioning from breastfeeding to bottle feeding.