The MAM Bottle Nipples and Anti Colic Valve Bundle includes 4 slow flow silicone nipples designed to resemble a mother's breast and 2 anti colic valve replacements compatible with MAM baby bottles. The nipples feature a unique flat, symmetrical shape based on ultrasound observations of 16 breastfeeding infants, allowing for a comfortable latch and easy transition between breast and bottle. They are made from skin-soft BPA-free silicone that 94% of babies readily accept. The 2 included extra slow and slow flow nipples are ideal for newborns. The anti colic valves regulate air flow to reduce colic, gas, and reflux. Their venting system creates a vacuum to eliminate bubbles. Made in Europe from BPA/BPS-free materials, the valves easily place and remove from all MAM Easy Start bottles for cleaning. With nipples designed for comfort and valves to reduce fussiness, this bundle contains complementary components to provide a complete feeding solution for your little one.