The Williams Legato III is a full-size digital piano with 88 touch-sensitive keys, Bluetooth Midi capabilities, i OS app and built-in speakers. More than just a great-sounding instrument for playing, practicing and performing, the Legato III includes sounds from the incredible Williams Custom Sound Library featuring a collection of impressive piano and vintage keyboards. The Legato III includes 10 of the best voices from this high-definition library. The dual-driver speakers deliver all those lush tones with outstanding and room-filling clarity and volume. And the Bluetooth Midi functionality connects wirelessly to your i Phone or i Pad to run educational software for additional learning. Plus, the Williams i OS app provides easy access to your Legato III advanced menus as well as self-teaching aids. The Legato III can run on batteries or with the included AC power supply.