This mod uses a mini toggle switch SPDT with an on/off/on configuration. This mod gives you two extra tone positions with very little modification to your instrument. You need to drill a 1/4" mounting hole then solder the red wire to the hot/positive signal any where along its path the black wire solders to ground. Its most often easiest to solder both wires to the jack red to positive black to ground. That's it and you will have tone that goes on for weeks. This switch can be built for any guitar or any bass just send a note with your instrument type/spec's I can build a custom switch to fit.