Check the listing for details. 10pcs 4mm x 6mm Potentiometer Control Knobs for Electric Guitar Grey. Condition: New. Listed at 10.39 USD. Rotary KnobProduct Details1.Instruction: Hold the handle and place the grinding head on the surface to be sanded and rub it back and forth.2.Advantage: These chain saw sharpeners are forged with diamonds, they adhere tightly to the surface and are not easy to fall off. The particles are full and evenly distributed, which ensures the stable and efficient grinding of the chainsaw, and is hard and not easy to wear. Wheel grinder replacement is easy to install and can be sanded without removing the chain. The grinding tool accessories save time and effort, and can effectively improve work efficiency.3.Color: Silver; Material: Diamond; Grinding Head Size: 20 x 4mm / 0.79 x 0.16 inch(L*D); Shank Diameter: 3mm / 0.12 inch; Total Length: 45mm / 1.77 inch4.Application: This stone file is suitable for surface graining, polishing, etc.