I was rummaging through a drawer the other day and came up with this wiring setup. I don't know how to describe this plug, hence, the picture. There are three pairs of wires coming out of this plug that terminate in phono plugs--two yellow and one red. Since they're phono plugs, I'm pretty sure it's audio-related. The metal portion of the plug is about 6mm wide. I'm sure it came with a piece of equipment but I've never used the plug. (I don't think I have. Hell, I'm 78. There's no telling.)
Any ideas?

Any ideas?

