I've been cleaning out my Pop's shop (he passed away) and I came across this. He was in communications his whole life which included 800 trunking, microwave & two way radio stuff. He built and owned repeater sites (he built the towers himself as well) I'm starting to sell all of the test equipment and looking into selling stuff like D.I.P. plugboards. There's no mystery as to what all that stuff is since it tells you right on it but this thing???? I don't have a clue. If anyone knows what this thing is and/or what its used for please let me know. Thanks