The BTS System by EMG is a full kit which contains a master volume control, a balance control, and then separate treble and bass controls (this is where it differs from BTC which is a stacked control).
It should be noted that the Balance control is an active control which is designed specifically for EMG pickups.
The Bass control additionally has a dual-dip switch which allows for four different configurations to customize your tone the way you want.
By using the latest technology, these control pots are able to be extremely quite (signal noise wise), and take only a little bit of current from your 9V battery.
The kit includes the 4 controls and knobs, as well as the corresponding solderless wiring kit (battery wires and output jack, 9V battery not included)