Pastix is a container for spaghetti with a mechanical iris mechanism on its cover.
The mechanical iris is a device similar to the diaphragm of a photographic camera. It has a sliding button that varies the size of the opening allowing different quantities on non-cooked spaghetti to come out of the container.
The sliding button has a scale numbered from 1 to 6, allowing measuring the quantity of spaghetti to be cooked for a certain number of persons.
Video animation of this mechanism can be seen here: http://www.youtube.com/watch?v=frKHYFXZXvQ