The Fender TBX (Treble Bass Expander) is a detented, stacked 250K / 1-Meg control that enhances your tonal palette without the use of a battery. Top quality potentiometers used on American Fender instruments. 3/8 potentiometer shafts. Mounting nut and washer included. Split shaft for compression fit knob. Each TBX Tone Control comes with a .022mf capacitor, 1-Meg resistor, White Tone Knob, Mounting Hardware and Installation Instructions.