Module under the passenger seat?

[Shapingo]

Ok,

I usually put air fresheners under the passenger seat and the other day I went to change a freshener and noticed a loose wire that wasn't connected to anything. Under further inspection, I saw that it was supposed to plugged into the module that is located under the seat. (I connected it back) My question is, What is the module?

Thanks in advance

 

[Jebus[tuning]]

It's the Amp for the stock Infinity sound system.