I've build and modified several guitars and used a Fender TBX Tone Control in all of them. They enhance your sound by adding more highs and lows.
In Short there are 2 tone pots stacked on top of each other, one will be used from 0 to 5 and will be the full sweep that would be on a normal tone pot.
The other one will be used from 5 to 10 and will add highs and lows to the sound.
The installation is very easy and anyone with some soldering experience, or who is a bit handy can do it.
The kit comes with all the parts, including a white tone knob, capacitor, resistor, potentiometer and an easy to use schematic.
I highly recommend this as an improvement to virtually any guitar. they work with humbuckers and single coils.