No, it's actually a fuse holder.

It's made of:
-Nokia BH-503 BT Headset (PCB only)
-LM317T
-470 Ohm resistor
-240 Ohm resistor
-TRS port
-four buttons

Basically, I had to power the device from my car, but it only runs on 3.7v instead of 12v. So an LM317T is used with two resistors to output the correct voltage. Then, the audio output has to be converted into something my car's head unit can read. So the two earth pins for earth speaker of the headset are earthed together (common earth), which is then connected to the earth of TRS port. The positive pins of each speaker are then connected their respective left or right channels of the TRS port. My head unit then plugs into this port through it's auxillary input. The four buttons are just extended as necessary, as they are actuated by bridging their respective contacts.

So, the on/off button is the top left button in the last picture (used a factory dash button), and the skip/track back, play/pause, skip/track forward buttons are the three illuminated buttons below my head unit.