The third largest of the instruments in the mandolin family, the mando-cello is tuned in fifths to the notes CGDA and resembles a ridiculously oversized mandolin. This tuning is exactly one octave below the tuning of the somewhat smaller mandola, and identical to the tuning of a cello. The only larger mando instrument is the mando-bass, an instrument rarely seen outside the mandolin orchestras of the 1920's and 30's. Many other mandolin related instruments were constructed in this time period, but none are considered members of the mandolin family proper.
Like all instruments in the mandolin family, the mando-cello has eight strings in four pairs (or 'courses') that are each tuned to the same note, usually an octave apart, but sometimes in unison. The tenor banjo, tenor guitar, mandola, and mando-cello can all be played using the same scales and chord shapes.
In ascending order of size, the mandolin family is as follows: mandolin, mandola, mando-cello, and mando-bass. This exactly parallels the violin family's structure of violin, viola, cello, and bass.