Product Description 6mm Metal Guitar/Bass Control Volume Tone Dome Knobs. Chrome metal flat top barrel knobs, bushing type, no screw hole on the knob. The Control Knobs are made of high-quality materials.  There are 16 grooved thick (18 tooth splined) shafts on the potentiometer. The threads inside are plastic and the outside is metal.  They are wear-resistant, durable and not easy to damage. They are the long-term partner of the guitar. It is suitable for most electric guitars and provides convenience for music lovers. Let instrument lovers enjoy DIY. Color:Bronze/Silver/Black are available. SIZE: The external dimension of the knob is 0.71 × 0.71 inch / 18 × 18 mm, inner diameter is 0.6mm (1 / 4 ").  Please take care of the size you need before buying. Package List: 4 Pcs Guitar Knobs As each monitor is different. There will be some color difference between the product picture and the actual one.