The Nuby no-spill insulated cool sipper keeps liquid fresh and cool and helps protect furniture from a "sweating" Cup. You and your child will be delighted with the Transition to cup drinking thanks to Nuby valveless, leak resistant design. The soft silicone no-spill spout is uniquely designed to prevent drips and spills while being delicate and gentle to your child's gums and new teeth. The pressure sensitive touch-flo feature regulates fluid intake with the sucking action of child- when sucking action ceases, the spout closes, ensuring a leak resistant cup.