IMP11-B ARPANET Interface
From Computer History Wiki
The IMP11-B ARPANET interface was a network interface produced by DEC's Computer Special System division for the a UNIBUS, which provided an 1822 interface; the latter could connect to anything that provided a BBN-1822 bit-serial interface, most commonly including IMP interfaces to ARPANET IMPs, but also Packet Radio Network interfaces.
It consists of a pair of hex boards, one a KMC11; they mount in an adjacent pair of SPC slots. Level converters allow use as either a Local Host or Distant Host interface.