Expand the sonic capabilities of your volume and tone controls and get control of your pickups without a battery! The PMT Passive Sonic Expansion Controls add a new dimension to your guitars controls without complex wiring or active electronics. Use the DMT Dual Mode Tone to add variable treble treble or bass cut at user selectable frequency ranges. Add the HCP Humbucker Control Pot to provide inner and outer North/South coil tap options of two humbuckers at the same time in varying amounts or select the filter modes to fine tune the frequency response of one coil of your humbucker while leaving the other coil at full range to explore new tonal possibilities. Add the V-Treb Variable Treble Bleed Circuit to your volume control and fine tune the tonal response at reduced volume settings while leaving the full volume tone unaltered.