This is a vintage 1967 Professional Concert Model SM 150 Petosa Accordian . It Can be Plugged into an Amplifier or a Speaker System (cord included ). The Petosa family have been making Quality accordians for 100 years . They started out in ITALY and eventually branched out to the U.S.A. This is a Full size accordian and is very well made .It still has plenty of Life in it and it gets Excellent Sound. The added Plus to this model is that it can be Amplified when needed for larger gatherings. If you are not familiar with Petosa accordians , I would encourage you to go check out their Washington Locations Website.I also encourage you to come and play test it for your own satisfaction. ( open to reasonable offers).