"Wiring harness" question

Ok so I know now which parts to get on the Lizardlick site to mod my SE fightstick. But I noticed in the description for the Sanwa Stick that I want to get, it says that it does not include the “wiring harness”. I’m not too sure what that is…do I already have that in my fightstick or do I need to get one so the new Sanwa stick will work? Thanks in advance for any answers.