: The GM3688 typically uses an RJ45-style connector (8-pin crystal head) that plugs into the microphone jack on the front of the radio.
Do you have a specific frequency range or signaling feature you need help configuring? Share your question in the comments below (if on a forum), or consult the official Motorola Professional CPS help file (F1) which contains detailed technical data. motorola gm3688 programming software download