PAC adaptor is a steering wheel control adaptor that allows the SWC to communicate to aftermarket radios. However it has dip switches and the instructions were pretty confusing.
I just installed an AXXESS ASWC-1, which is a lot simpler to install:
https://amzn.to/4aekZqV
I'll make a seperate post about it with my thoughts on it, so it's easy to find with a search.