Suzuki Tonechimes 4th octave expansion setIntroducing the Suzuki Tonechimes 4th octave expansion set This is a smaller, expansion set of hand chimes which has been created to work in addition to the HB 250. HB 12A 3rd octave expansion kit sets of chimes. The HB 250 is the core set of 25 notes which encompass G4 G6. The HB 12A expands this set at both the bottom and the top. The HB 12B further expands these two sets at the bottom, G3 B3 and at the top C#7 G7. It is important to remember that