Our customers have requested remote controls for our older manual amplifiers or other manual amplifiers. What to do? So we built a control box. Not only can you control the volume of the amp, but the JD5T can be used as a preamplifier with 10db of gain, There is remote on/off, mute, and standby, plus two AC receptacles, and two outputs which now make hooking to a subwoofer or bi-amping an easy procedure. With a low profile and a full body you can put another component or amplifier right on top, no need to use another shelf.