• The Model 60 EIA Interface Monitor and Breakout Box
  can access all 25 conductors of the EIA RS-232-C and
  CCITT V.24 interfaces between the data terminal and
  the data modem.
• Twelve LEDs monitor key EIA signals.
• Two additional LEDs monitor any positive or negative
  signal and indicate whether or not it meets the EIA
  specifications.
• Twenty-four miniature rocker switches allow you to
  interrupt each interface signal for testing or
  cross-patching with Piggy-back stacking jumpers
  (provided in the unit)
• You can also use the Model 60 to make prototypes of
  special cables, such as null-modem cables.
• The model 60 comes in its own case and is powered by
  two AA size 1.2V NiCad batteries which provide 100
  hours of continuous operation.