For those who don't recognize the device, it's a DexDrive.
It was somewhat popular back in the day since it allowed
PS1 saves to be transferred to and from a PC, making the
space for storing your saves "limitless".
Anyway, almost all major PS1 Memory Card editors support
direct communication with DexDrive. I've always wanted to add that feature to MemcardRex but due to the lack of a said device I was unable to...
Until now. So for MemcardRex 1.6 expect a DexDrive support ;)