Features: Potentiometer knob is suitable for 6mm diameter shaft, used for Volumes, control knob, guitar Volumes tuning knob. Suitable for easily assembly onto potentiometers, ensuring smoother rotation and enhanced control. It is make of Plastic, durability, and can be used for a long time. Easy to install, very enduring, and will not affect the use of your instrument. Great for upgrade or replacement part. Practical replacement knobs are a great gift for those who need knobs. Specifications: Material: plastic Color: Black/White/Red Size: As shown Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 6Pcs Guitar Effect Pedal Knobs