Features: 88 keys Piano with Midi interface. Has 23 demonstration songs, 100 kinds of rhythm, 128 kinds of tones and 12-stage volume adjustable. Built in louder speaker. Also with earphone jack, can connect with external speaker. LED digital display. Can be rolled up for easy storage and carrying around. Specifications: Keyboard model: 88 keys; Tone: 128 Rhythm: 100; Demonstration songs: 23; Powered by: 4 x AAA batteries(not included) or DC 5V