This harmonica tray can fit up to 14 diatonic next to each other, there are 12 on the pictures
With 12 harmonicas you still have room to move them around easily, very robust.
15.3 inches by 4.9 inches
HarmonicaTray. Attaches to pipe diameter of 30 mm. Surface protecting clamping element. Aluminium version. Shelf: 390 x 120 mm Stuck inside with felt. Weight: 0.5kg Colour: Black.