Forum dedicated to the Harris PSPC Product group items such as Orion, M7100/M7200/M7300, P7100/P7200/P7300, Harris Unity XG-100, GE Orion, GE Master Repeaters, EDACS Trunking, Pro Voice, PC Configure, RPM, and other topics relating to Harris, MA-Comm, Ericsson, GE products.
Likely it's the larger one for audio. It sounds like a regular ham radio style speaker mic. The PTT and mic are all combined into one cirucuit on the tip of the smaller pin. When it's grounded it activates the ptt and puts the mic cartridge in line in the circuit.
The larger pin is just simply speaker audio out with the tip + and ring -