Hello all! I've just bought a few parts for my PC build, which can be found here, https://pcpartpicker.com/list/QCbkqk I don't know what 2 of the parts are though. Those black things. (Are they separators?) And... I know that it is for a speaker, but what do I do with the pin hole on the back? What do I plug in it? Thanks! And sorry for the noob question.