This object has a metal frame, open on both sides, and a door on the back. The front two-thirds of the frame contain a roll-out unit with two hinged card cages. The cages are filled with IBM modules. At the top there is an orange add-on bracket with one screw protruding from the middle. The back third of the frame is for cabling.
International Business Machines (IBM)
Found on a label on the front right door of the unit.