Karman high quality heavy duty B500K 15mm Split Brass Shaft Full Size Potentiometer for volume and tone control on guitar.

Measurements on diagram:

D3 = Pot diameter: 24mm (full size)

L = Shaft length: 15mm

D1 = Shaft diameter: 8mm

D2 = Shaft diameter for knob: 6mm (split)

250k pots are usually used for volume control and tone control on single coil pickups

500k pots are usually used for volume and tone control on humbucker type pickups

Split shafts are suitable for push-on control knobs, solid shafts are suitable for knobs that have a tightening screw.

15mm Shaft pots are normally used for Fender style guitars or guitars with plastic pickguards that the pot goes through

18mm Shaft pots are normally used for Gibson style guitars as they often have wood that the pots must go through.