The object is an IBM 700 series vacuum tube module. These modules were used in 701, 702, 704, 705, and 709 computers. The module consists of a steel front plate with miniature tube sockets. There is a plastic connector located about 5 inches behind the front plate. A plastic frame between the front plate and the connector supports 4 tiers of terminal strips. The connector has a locking cam on a shaft which protrudes through the front plate. There are2 empty socket holes. Below these holes is a heat sink with a power transistor connected to a small batch of discrete components probably comprising a voltage regulator.