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. At PIGEON, we believe that stretchability is the most important function of an artificial nipple in encouraging baby’s natural suckling. Ultra-Soft Siliconee: The nipple’s surface is very soft, yet it does not collapse easily. Made from thick ultra-soft Siliconee material, the nipple has similar elasticity to that of a mother’s actual breast. The dome-like shape makes baby’s mouth open naturally, supports its mouth softly and fits its lips gently. Recommended by leading Dental Practitioners, Childbirth Educators and Paediatricans around the world.Size Medium (Peristaltic Nipple Variable Flow). Ideal for a 2 to 3 months baby.