Ramune is widely known for the distinctive design of its bottle, often called Codd-neck bottles after the inventor, Hiram Codd. They are made of glass and sealed with a marble; the codd head is held in place by the pressure of the carbonation in the drink. To open the bottle, a device to push the marble inward is provided. The marble is pushed inside the neck of the bottle where it rattles around while drinking. Therefore, the drinks are sometimes called “marble soda” outside of Japan.