Trapezoidal salterio with extension on the LH side for suboctave strings. Black-stained frame of beech with ?spruce soundboard. Two soundholes. LH extension of two posts tenoned into side of main instrument with cross-piece forming a hitchrail for the sub-octave strings; this frame encloses an additional quasisoundboard. There is a thin backboard close behind it. The surviving bridges, are formed of slotted strips of gessoed and gilded beech, of various lengths, two sections for the RH set, and four for the LH set. Brass wire provides a bearing for the strings. There are 24 quadruple-strung courses arranged to give a compass of approximately thirty notes. The twelve courses on the RH bridges give one pitch per course.
Length: 985mm. Width: 341mm. Height: 129mm.