The Akai AP-M313 is a USB/MIDI keyboard controller that combines the functionality of a computer keyboard, a MIDI controller, and a USB hub into one device. It features 31 semi-weighted keys that provide a realistic touch and response, as well as a range of MIDI controllers such as knobs, sliders, and buttons. The keyboard also includes a compact USB hub that allows users to connect up to 3 additional USB devices, such as a mouse, headphones, or a hard drive. The AP-M313 is compatible with both Mac and Windows operating systems and is a versatile and convenient choice for musicians, producers, and studio engineers. It enables users to integrate their computer and MIDI hardware into a single efficient setup, and offers a premium feel and performance for its price point.Some of the key features of the Akai AP-M313 include:- 31 semi-weighted keys with aftertouch- 14 assignable MIDI controllers, including knobs, sliders, and buttons- Compact USB hub with 3 additional USB ports- Compatibility with Mac and Windows operating systems (requires a driver for Windows)- class-compliant MIDI and USB connectivity, no drivers needed on Mac- Sustain pedal input- Power source: USB bus powered (no additional power supply required)- Dimensions: 40.8 x 9.8 x 1.9 inches (103.6 x 25.0 x 4.9 cm)- Weight: 3.2 lbs (1.5 kg)Overall, the Akai AP-M313 is a user-friendly and feature-rich MIDI keyboard controller that provides a price-competitive and high-quality option for a wide range of musicians and music producers. Its compact size and versatile connectivity make it an ideal choice for a variety of recording, live, and studio environments, while its compatibility with various operating systems ensures worldwide use.