2pcs Potentiometer Knob Knurled Shaft Silver Tone Aluminum Smooth Surface Package Dimensions: ‎5.2 x 3.82 x 0.75 inches Replacement knob for potentiometer with knurled shaft. This plastic control knob is designed to be assembled onto a potentiometer, making rotation easier. It can be used to adjust various functions like level, speed, and voice. The knob fits 1/4" (6mm) shaft pots and works well as a speaker control knob.