These 2 pack 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 insulated cups have interchangeable lids, which means you can keep the cup even when your child has grown out of a sippy cup spout.