Pigeon S-Type Nipple Medium is made from thick ultra-soft silicone material. The nipple has comparable elasticity to that of a mother's actual breast. The dome-like shape makes baby’s mouth open naturally, cares the mouth softly and fits the lips softly. Pigeon S-Type Nipple is super-stretchable with slow flow. Teat section has an 'accordion-like' portion that enables it to stretch in response to the peristaltic movement of the baby's tongue.