Treble Bleed - Volume Mod Experimental Kit
Because of how a guitar circuit works, when you turn the volume down, some of the high frequencies start to disappear. Some people like this effect and some do not.
The Volume mod is a Capacitor and a resistor that you add to the volume pot on your guitar. This acts to counteract the effect of "lost high end"
This kit includes two different "volume mods" for you to experiment with (pot values, taper, pickup type, and other things make the results a bit variable)
470pf Capacitor and 220k Resistor often used with single coils
.002uf Capacitor and 150k Resistor often used with humbuckers
2 Aligator clip leads
This will allow you to experiment without soldering until you are sure which one you like based on your current rig.