IK Multimedia iRig KEYS 37 velocity-sensitive mini-keys (3 full octaves range plus one note) Core MIDI (iOS) and USB class compliant (Mac/PC) - plug and play Powered from the iOS device or Mac/PC USB Comes with SampleTank FREE iOS and iGrand Piano FREE apps (download from the App store) Comes with free Mac/PC virtual instrument: SampleTank 2 L (download from IK User Area)