Tommee Tippee Superstar Insulated Straw Cup Pink encourages sipping which supports a healthy development of the mouth, jaw and teeth, featuring INTELLIVALVE™, a unique anti-leak technology which guarantees this drinking bottle is completely leak-proof as it withstands internal pressure meaning the bottle won’t leak even when it is turned upside down or shaken. The unique valve both seals and regulates the flow of liquid to stop leaks and to ensure easy drinking.