Guardelli Sound Modulator - magnetic cello wolf tone eliminator

• Guardelli Sound Modulator - magnetic cello wolf tone eliminator

Guardelli Sound Modulator consists of a high-power neodymium outer magnet embedded in a wooden shell , a metal installation rod and an internal tube with magnetically levitating piston which inserts inside the instrument through the left/ bass f-hole and gets magnetically connected with the outer magnet for smooth manipulation across the top plate surface.