This is a SCSI 50-pin black terminator for 68k Macs. It was used with a Macintosh IIfx. While there are many types of SCSI terminators, both genuine and aftermarket, the fastest 68k Mac, the IIfx, could only use this specially made, expensive genuine black terminator, making it a rare and valuable item. Even now, it is traded at high prices, especially among vintage collectors in the United States. Although the fixing pins for the cable are missing, I used it by simply plugging it into the SCSI cable from an external HDD. I can't confirm its operation now as the IIfx is broken, but the structure is simple, so I think it should work. However, please consider it as junk. Please note that the IIfx body shown in the photos is not included in this listing.