Your little one will find the transition from bottle to cup an easy one with the soft silicone spout and unique contour that easily fits their small hands. You will be delighted with the transition thanks to Nuby's valveless, leak resistant design. The soft silicone spout is designed to prevent spills while being gentle on baby’s gums and emerging teeth. The pressure sensitive Touch-Flo feature regulates fluid intake with sucking action of child. When sucking action ceases, the spout closes, ensuring a leak resistant cup.