3-10oz, Pink, Blue & Green Nuby’s silicone spout is perfect for spill-prone little ones. The built-in touch-flo valve is pressure-sensitive and designed to open when a child drinks from the cup. When sucking action stops, the valve closes, keeping dribbles and spills at bay. Nuby’s designer series features bright colors and beautiful designs. The fun, unique designs will delight you and your little one.