The part number Bailey Controls 6642016x2 (where "x" serves as a placeholder for revision letters like A, B, C, or D) identifies an External Relay Panel / Termination Unit belonging to the legacy Bailey Infi 90 / Network 90 Distributed Control System (DCS), which is now owned and managed under the ABB Bailey Heritage Brand.
Common Revision Variants: You will frequently see this listed in parts inventories and surplus sites as 6642016A2 or 6642016D2