Favorite Disney characters will make this your little one s favorite cup. These 9 oz. cups feature double layer insulation to keep liquids cold for longer and a sweat-proof design that makes the cup easier for kids to grip. Moms will love the easy-to-clean One Piece Lid, with built-in valve and no small parts to lose. And to make life even easier, all of The First Years reusable cups with One Piece Lid are interchangeableÃ¢?"which means you can keep the cup even when your child has grown out of a sippy cup spout.