The Hosco 500K Push/Push Audio Taper Potentiometer packs two functions in one, the pot works as normal on its own but built in is an independent double pole double throw (DPDT) switch which can be wired to add/remove pickups, coil splitting and tapping, series/parallel switching and phase switching just by pushing down on the guitars control knob. This Push/Push is a more convenient version of the traditional push/pull pot as it is easier to activate, you simply push on the top of the knob regardless of which position the switch is in rather than having to grab and pull up on the knob for a push/pull (this is especially useful on smooth side knobs like Gibson hat knobs) and it means there's less chance of accidentally changing the potentiometer's setting while changing the switch position. The 500 K Ohms resistance gives a brighter tone and traditionally used for humbucking pickups and its logarithmic audio taper is normally used for volume pots so the human ear can hear the volume change more smoothly (though now commonly used for tone pots as well). These have an imperial 3/8" threaded shaft (commonly found on guitars made in the USA like Gibson, Fender and PRS Core) but please note these have metric coarse 18 spline knob mounting and so to replace the pots with a 3/8" shaft you will also need replacement metric knobs (pots with an imperial 3/8" shaft normally have fine 24 spline knob mounting). To use metric knobs that have a set screw simply line up the set screw with the split in the shaft and tighten the screw. Knobs should only be removed while the switch is in the up position. Mounting hardware is included.