Our high quality microphone system including a preamplifier to boost volume output for self fitting.  It features 3 electret microphones which you attach inside the grille of your accordion, 1 electret microphone which you fit to the bass of your accordion, a 9v battery which clips inside your treble grille and a standard 6.3mm jack plug connector which you fit to the grille on your accordion (instructions are provided for fitting).