A close-quarters weapon which slices through objects it contacts at the molecular level using a blade formed of high-frequency vibrating particles. One of the standard armaments for Eva, it is normally housed in the shoulder portion. Eva-02 uses a new cutter-type knife -- even if the blade breaks off, a spare blade can be extended, making the knife usable again. It is often called by its abbreviated form: Prog Knife.

Source: The End of Evangelion : Glossary contained within The End of Evangelion - Theatrical Program.