●Fits electric guitar, bass, and other instruments with dual concentric pots for most common concentric pots ●Top knob size: outer diameter 0.7 inch (19 mm), high 0.5 inch (13 mm), inner diameter 0.2 inch (6 mm), compatible pot shaft diameter: 0.2 inch (6 mm) ●Lower knob size: outer diameter 1.0 inch (25 mm), high 0.4 inch (10 mm), inner diameter 0.3 inch (8 mm), compatible pot shaft diameter: 0.3 ●Material: Steel, sturdy and durable. Brass shaft hole and set screws included ●Package included: 2 pcs