Radio conversion (bose plug)

Hello, guys!
Yesterday afternoon, I expanded the old radio (some retrofitted Uralt pioneer) of my thickness, because I wanted to install my blue point.
All I could find in the built-in shaft was an orange cable (think +) and four round, multi-pole plugs.
Where do I get such adapter plugs now so that I can connect my blue point?
Are the four round plugs the Boseleitungen ?
Greetings Hannes