Features:- A)PIGEON Peristaltic nipple was designed based on advanced nursing research and study to provide the best for mother and babies. B)Super -Stretchable Teat section has an "accordion-like" portion that enables it to stretch in response to the peristaltic movement of the baby's tongue. C)The nipple's surface is very soft, yet it does not collapse easily. Made from thick ultra-soft silicone material, the nipple has similar elasticity to that of a mother's actual breast. D)The dome-like shape makes baby's mouth open naturally, supports its mouth softly and fits its lips gently. E)Recommended for newborns up to three months old baby for slow flow.