Audio Systems: aux input, infinity sound, chrysler dodge

Question
I have a 2004 Dodge Ram with infinity sound system and factory 6 disc in dash cd changer. What auxiliary input device do I need?

Thanks Mark

Answer
If the radio is capable of controlling an external cd changer use this
http://www.oemautosound.com/p-40-chrysler-dodge-jeep-auxiliary-audio-input-adapt

if your radio is Sirius satellite radio you need this part
XMDCHY100