The CMC 7900 BUTT-IN II has a case constructed of a high-impact plastic and the internal electronics are packaged for the rugged treatment it receives in the field.
The keypad is constructed of a water-repellent rubber and the case is designed with tight-fitting joints to prevent moisture intrusion.
The BUTT-IN II provides either DTMF or Dial Pulse output. The Pulsing Mode is selected by a Mode Switch (Tone/Pulse). A Talk/Monitor switch permits an off-hook condition for dialing and talking or a line monitoring function for monitoring the line without disrupting conversation, data or signaling.
Two colored (red and green) Light Emitting Diodes (LED's) and a push-button switch (Polarity) provide a quick visual check of the circuit polarity.
A Mute Switch allows the caller to shut off the transmitter for improved hearing from noisy locations. The last number dialed can be redialed by simply pushing a button on the keypad.
An extended range switch allows the caller to extend the range of the test set when testing exceptionally long lines.
An optional Ringer provides an audible ringing tone when the BUTT-IN II is in the Monitor mode.
The CMC 7900A BUTT-IN II is provided with a five foot cord with insulating piercing alligator clips. The CMC 7900B is equipped with a one-foot cord and 346A plug to allow cord changes, and the 7900C is equipped with insulation piercing (spike and cluster of needles) alligator clips.
CMC's sturdy belt hook is easily replaced without disassembly and clips around a 7/16" strand.