Zhāng Kūn (张昆), a zheng maker at the Shenyang Musical Instrument Factory, created the first functional modulated Key-Changeable zheng. Mechanisms near the head of the instrument, by the player's right hand, could change the tension of strings. Unfortunately the action also changed other aspects of the sound and not in a good way; the instrument was never mass produced. Alas, I have no photograph of it!