This is a PXI-2501, 48 Channels, 48-Pin SCSI I/O Connector, PXI Multiplexer Switch Module for the National Instrument PXI modular system.  The board was removed form a large automatic tests system that was decommissioned and it is used. The sale also include the TB-2606 terminal block. Since the board is used, performance and calibration is not guaranteed.