Korg keyboard microKEY Air-25 controller. Natural Touch mini-keyboard 25 keys. Controllers: Joystick, arpeggio button Sustain / TAP button Octave buttons. Eighth Change -4 – +4. Connections USB Type B (x1). Wireless Protocol Bluetooth Low Energy (meets the specification Apple Bluetooth Low Energy MIDI). Power: Two AA batteries (when connected wirelessly, use alkaline batteries or nickel-metal hydride). USB bus power (when connected via USB). Power Consumption: Less than 100mA. Battery: Approximately 30 hours (with alkaline batteries). Dimensions (W x D x H): 395 x 131 x 52 mm. Weight (without batteries): 670 g. Included items: USB Cable, Software Bundle KORG code. Performance requirements (wireless): Mac that supports Bluetooth 4.0 or later and OS have X10.10 Yosemite or later installed; iOS: iPad / iPhone that supports Bluetooth 4.0, and have iOS8 or later installed; We plan to develop a MIDI Bluetooth driver for Windows, however we can not confirm a release date. We will announce it as soon as the planning is confirmed. Operating Requirements (USB connection): Windows: Microsoft Windows 7 SP1 or later (32-bit / 64-bit); Mac OS 10.8 Mountain Lion or later; iOS8 or later.