This is a very cool item. It's a model TMB-250 PCMCIA card reader for your home PC. Manufactured by the Envoy Data Corp. You install the bigger card shown above in a standard drive bay, insert the smaller card above in an ISA slot, and connect them internally using the cable provided. Voila! You can use PCMCIA cards on your PC. Note that this requires you have a PCMCIA slot on your PC.
Kit is new but opened. Comes with everything you see: Card reader, ISA card, cable, mounting brackets, power cable adapter and manuals.