This is a vintage 1989 Casio MT240 PCM MIDI Synthesizer Keyboard, also known as the Casiotone MT 240. It is a classic electronic keyboard produced by Casio. This keyboard features MIDI capabilities and PCM sounds, which were innovative features for its time. With its retro design and sound, this Casio MT240 is a sought-after piece for collectors and musicians interested in vintage musical instruments from the late 1980s. This keyboard does not have a battery door.