Good replacement fader knobs, easy and convenient to use. knobs a better fit and more secure for use. Product Name: Fader Knob; Size: Inner hole 4mm Material: Plastic Color: Gray Package Contents: 200 x Potentiometer Cap Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.