Breakout box for testing the Manned Maneuvering Unit (MMU) Control Electronics Assembly (CEA). (The CEA would read astronaut hand controller inputs, or gyro
inputs when it attitude hold mode, to drive the thrusters of the MMU.)
Consists of rows of test point jacks mounted on a metal box, with internal interconnecting wires.
Allowed testing of the signals on each circuit of the cable and connector.