Flexible Roll up piano/Roll up Electronic piano/Portable Roll up piano Inner connection of amplifier: earphone/amplifier(Home Theater) can be connected externally. Power supply: Energy saving design. Inbuilt 4 AA batteries. Available for outer connection of power. Now with new and improved touch keys you can feel key response similar to a real keyboard! For piano musicians on the go, brand new piano students, or people just wanting the latest and greatest in musical tech. This completely flexible synthesizer piano can roll into a super compact design for storage and for moving. With 61 standard layout piano keys, 128 different synthesized tones to choose from, 100 different rhythms to play with, and other features like MIDI and Speaker OUT as well as a 3.5mm headphone jack, this portable piano synthesizer is comparable to any high end digital piano at a fraction the price and with so much more in gadget factor. A perfect gift for the musician in your life.