United States Air Force, Cambridge Research Laboratories
overall: 3/4 in x 4 1/2 in x 6 in
There are three tubes on one side with seven wires connecting them each to the board. There are also resistors and four transformers on one side. On the other side there is a printed circuit. Handwritten on solder side is " OK scw 3/59". Handwritten in red paint on the edge of the frame is "TRANSFER UNIT".