Nuby Natural Touch Silicone Replacement Nipples - Fast Flow - 2 pk Natural Touch SoftFlex nipples are designed to make breast and bottle feeding easier to combine, offering the very best for your baby and the flexibility you deserve. The breast size natural shaped nipple encourages your baby to latch on like the natural action of breast feeding and the nipple flexes, stretches, and moves just like mom"s breast. They feature superior anticolic valves in the base of the nipple which help prevent colic, and soft nubs on the surface to massage baby"s gums.