Rino 750 Spk/Mic

[Rapserv]

Have recently purchased a couple of Garmin Rino 750 GPS/UHF units and want to be able to use them with a speaker/microphone. Does anyone know of a particular brand that will work with the single connector as used on the Garmin.
I am aware of the Garmin earphone/boom mic and bluetooth systems but they are not suitable for my needs as I am wearing headphones.

 

[Nuvi-Nebie]

You would need to buy / make something compatible with the Rino 2.5mm 3 way jack socket, this appears to be compatible with Motorola M6 devices and would have (I guess), GND / common, microphone / push to talk and mono speaker / headphones connectors