A harpsichord is a musical instrument played by means of a keyboard. This activates a row of levers that turn a trigger mechanism that plucks one or more strings with a small plectrum made from quill or plastic. The strings are under tension on a soundboard, which is mounted in a wooden case; the soundboard amplifies the vibrations from the strings so that the listeners can hear it. Like a pipe organ, a harpsichord may have more than one keyboard manual, and even a pedal board. Harpsichords may also have stop buttons which add or remove additional octaves. Some harpsichords may have a buff stop, which brings a strip of buff leather or other material in contact with the strings, muting their sound to simulate the sound of a plucked lute.