Original Apple new-old-stock NUBUS multi-port serial card and matching 4-port "Hydra" cable for connecting up to four modems to any Macintosh with a full length NUBUS slot. This uses a proprietary 62-pin D-type connector connected to four 25-pin D-type male serial connectors.
NOTE: Although we believe this NUBUS card has never been used, the breakout cable was not stored in a bag and so was quit grubby. We have cleaned it up but be aware that the cable may not look new.