Casio Casiotone CT-360 keyboard

Untested keyboard. Requires 9V DC (centre negative). Sold as is.

Description below from AI: 

Key Specifications & Architecture

• Keyboard: 49 full-sized keys (4 octaves, synth action, non-velocity sensitive). 
• Polyphony: 8-voice polyphony (meaning you can play up to 8 notes simultaneously before older notes cut out). 
• Sound Engine: Early digital PCM synthesis. It features 12 preset tones and 12 auto-rhythm patterns. 
• Hardware layout: Features a single built-in speaker on the far left, a master volume slider, an accompaniment volume slider, and a traditional 1/4-inch output jack on the back panel for external amplifiers or headphones.
• Power Options: Can run on a 9V DC adapter (typically the Casio AD-5) or via true retro style using six D-size batteries.

The Highlights & Quirks

• The "Casio Chord" System: Like many keyboards of its era, it features an auto-accompaniment section (the lower 1.5 octaves). If you switch it to Casio Chord mode, you can play full major, minor, and seventh backing chords with just one to three fingers. 
• Unique Arpeggios: While it only has 12 rhythm styles, each rhythm triggers completely different automatic basslines and chord arpeggios depending on what style is selected, making it surprisingly fun to jam with. 
• Built-in Auto Power Off: To protect battery life, the unit automatically cuts power if a key hasn't been pressed for roughly 6 minutes. (You just flip the physical power switch off and back on to revive it).