See pics.  No power supply included.  Does take batteries.

Introducing the Realistic Drum Machine Rhythm Box Concertmate 42-2103 Accompanist Metronome. This vintage instrument from 1981 is perfect for beginners and features push-button action, built-in speaker, presets, and battery-powered option. It comes in black color and belongs to the Electronic Keyboards category under Musical Instruments & Gear.

With the Realistic Drum Machine Rhythm Box, you can create amazing beats and rhythms without the need for keys. Its features include a metronome and a range of presets that can be easily accessed through its push-button interface. This instrument is a must-have for any musician or music enthusiast who wants to experiment with different sounds and beats.