7 oz Spill-Proof Cups. Color Change. Magically changes color with cold liquids. Easy-grip tapered shape for little hands. Easy-sip firm spout. Lid and valve fit other spill-proof cups. Easy to clean silicone valve. Liquid flow is activated by child sipping. If cup is held upside down, a few drops may come from spout. Carbonated beverages are not recommended for use in this cup.