The special model is comparable to the Péguri/Manoury system. On the right of the treble, however, the inner 3 rows are not a C fingering, but a B fingering. In the bass, the direction of play of the C fingering of the inner 3 rows is opposite to that of Péguri/Manoury and the 2 outer rows have a different tone assignment. Possibility of comparison on bandochords.de