This official Fender CTS 250K/500K Concentric Audio Taper Solid Shaft Potentiometer allows for more complex electronics circuits and is used on American Vintage '62 Jazz Bass, Acoustasonic Telecaster and Nashville Power Telecaster guitars. Concentric pots are two independent potentiometers stacked together with two stepped shafts for attaching concentric control knobs (these require imperial knobs with set screws), the larger diameter shaft controls the top pot and the thinner shaft controls the bottom pot, the two shafts/pots are not connected meaning each pot can be adjusted without affecting the other, for example with this 250K/500K potentiometer the 500K pot could be used for a humbucker volume control and the 250K pot could be used for single coil volume control in a HSS pickup guitar. The short threaded bushing is useful when mounting to scratchplates and control plates to ensure the knobs do not sit too high above the body.