An Open Diapason of 4' pitch on the manuals, or 8' pitch on the pedal. These names have also been given to the stop more properly called Super Octave or Fifteenth. The name Principal is more properly used as a synonym for the Open Diapason. The name Prestant often indicates that the pipes are mounted in the front of the case. The word Octave is often used as a modifier with other stop names to indicate a stop at a pitch one octave higher than normal, but the word by itself invariably refers to a Diapason.