Need answer to question about XM Sportscaster radio
 

I got a sportscaster XM radio, the FM mod a dum a gigger is too week, I'm constantly having to switch frequences-- so I want to use the headset and plug into the Aux imput of my dash radio, question is-- is that jack on the sportscaster a special jack? I really can't tell, and lost the paperwork on the radio...looks to big for a standard headphone jack---anyone know for sure?