XM2GO Delphi and Used Car

I just bought a used car that came equipped with a prewired satellite antenna. I went to plug my XM2GO device into it but the connector on the prewired antenna is larger then the port on the XM2GO device. Is there an adapter I can buy? I am not sure how to figure out which adapter to buy?

Please advise

Thanks
Paul

Based on what I can figure out the antenna in the truck has an SMB connector and the jack on the XM2GO unit is a SSMB type. Is there a SMB to SSMB adapter so that I can plug my XM2GO into this prewired antenna?