What is this?Potentiometer knob is an important accessory for connecting potentiometers,fit for 6mm D type Shaft and can be used for electric guitar, bass, audio,amplifiers,volume control, etc.What will I get?Potentiometer Control Knob ,is in size of:Height:15.5mm(0.61 inch)Outer diameter:12mm(0.47 inch)Inner diameter:6mm(0.23 inch)Color:Black YellowMaterial:ABSButton rotation degree:270 degreesIn the package of: 20 x Potentiometer Control KnobIs there any advantages of the product?It is made of ABS material,which has high reliability and durability. Button beautiful appearance, small size, easy installation, suitable for a variety of different electronic equipment and occasions. How to use it?Steps of using:1. Confirm the potentiometer model; 2. Insert the potentiometer knob cap into the top of the potentiometer knob and rotate gently in accordance with the direction to confirm whether the knob is firm; 3. By rotating potentiometer knob cap, realize the adjustment of sound effect. What should I notice?Notes:In the use of potentiometer knob need to pay attention to choose the appropriate model and size, confirm the direction and position, gentle and smooth operation, prevent water and dirt.