The Treble Bass Expander (TBX) is a stacked and detented 250K/1Meg potentiometer that expands your tonal palette. It functions as a standard tone control from 1 to 5, after which it decreases resistance, sending more bass, treble, presence and output to your amp. Mounting hardware and installation instructions included. No battery necessary. White "tone" control knob, .022mf capacitor, 1/4-watt resistor, mounting hardware and installation instructions included. Brand New. Genuine Fender 0992052000. UPC 717669448011. Photo may not reflect current Fender packaging.