This thing is amazing!  Self contained.  It runs on two 9 volt batteries, although it does work on just one battery, but there is a jack on the back to connect an external power supply like one of those ‘wall warts’ you have lying around the shack.  It is great for learning morse code… when you change the speed knob, the speed is indicated on the meter; and you can adjust delay to change spacing between letters, on/off volume control to a small built in speaker, plus you can plug in a keyer and output to a transmitter.  You can see the front says ‘morse code teaching computer/keyer’  It is intuitive to use, but it would be nice to find the manual for it.  I took the cover off to show the inside.   You would be hard pressed to find another one of these anywhere.   A fully operational collectors item that is still very useful….. thanks for looking… regards…. Ron