My father—in-law was an electrical engineer and had a great collection of audio and electronic equipment. I’m not sure what this is. Can anyone help?
It has a cable with 3 connectors on one end that would fit in the 3 ports on the front. The other end of the cable has red and black clamps that look like little jumper cables. There is a switch on the top like the one in front, but without a label. It fits into a nice wooden box.