SM10 or Freewire

[DMAGOLDRDR]

That is the correct adapter to use.
Next the Sena sm 10 is great if you are going to add a GPS that has a 3.5 cord out you can plug that in to sena sm10 and it will over ride your music for directions.
Plus you can blue tooth it to two helmets so your rider, if they have a Bluetooth devise can listen to the music also. Also you will be able to answer
two phones one for you one for her on separate helmets.
The only addition that the freewire gives you is the ability to use your CB if you have one coming through your 5 pin din cable.

Correct 1.5 ft long worked perfect.

Thank you both for helpful info. Going wireless may not be as expensive as I thought.