Roland FR-4X BK V-Accordion (Black with Keys)37 keys and 120 left hand buttons Compact and lightweight Sound module and user interface from the flagship FR 8xb 100 accordion sound sets (including 67 pre loaded sets), 162 orchestral sounds, 32 organ sounds, 3 drum sounds Built in chorus, reverb, and rotary effects Fast response and high sensitivity from bellows pressure sensing circuitry Bellows Resistance Regulator to adjust bellows inertia Character type LCD screen Four expansion slots for