The Watkins MIDI Partner dedicated Accordion expander.   

Easy to use, just plug in and play - 5 minutes and you will be sounding like a band...........
Midi Partner Price : 625

Optional 4 way control pedals 125. These allow you to control any of the front panel buttons with your feet.

   
Specially made 'by accordionists for accordionists', the Midi Partner is probably the easiest and best sounding accordion expander there is.
See the basic Midi Partner instructions sheets HERE.

We have a dedicated website with lots of information about the Watkins Midi Partner at www.accordionexpanders.com , click this link to go there.