The object is a well ventilated steel case containing a power supply and a large circuit board. The board has a Motorola MC68000 CPU. There are connectors for ribbon cables. A ribbon cable with an Apple II interface card is part of the lot (separate record).
For more information on these object refer to the wikipedia entry for "DTACK Grounded" (https://en.wikipedia.org/wiki/DTACK_Grounded). The board is an "attached processor" allowing a Motorola 68000 and memory to be used from an Apple II. It was designed by Hal Hardenberg and sold via his company Digital Acoustics (apparently not related to the company of the same name in 2019)