The Casio CTK-491 has61 Full-size Keys12 Note Polyphonic100 sound tones and 100 rhythm patternsCasio chord and fingered chord auto-accompanimentMic input and seperate volumeMIDI in/out jack2 Built-In speakers and 1/4" line outputHeadphone jack and sustain pedal jackDisplay shows notes, tone status, finger position and moreUses AA batteries or optional AC adapter