These instruments are typically owned by some kind of organization or investment group, which may loan the instrument to a notable performer.
It attaches the strings to the lower end of the cello and can have one or more fine tuners.
Other notable examples include 's and 's Sonatas for Solo Cello, Dutilleux's Trois Strophes sur le Nom de Sacher, Berio's Les Mots Sont Allés, 's Suite for Solo Cello, Ligeti's , Carter's two Figments and ' and Kottos.