Features: 1.Made of quality metal material, wear-resistant, sturdy and durable. 2.Adopt fine workmanship and delicate design, smooth surface, will not scratching your guitar. 3.Lightweight, easy to install and use. 4.Perfect used as guitar and bass tone control knobs and volume control knobs. 5.Great replacement for electric guitar and bass. Specifications: Material: Metal Color: Silver Mounting Hole Inner Diameter: Approx. 6mm/0.2in Size(Diameter*Height): Approx. 18.2*18mm/0.7*0.7in Package list: 4 * Volume Control Knob 1Made of quality metal material, wear-resistant, sturdy and durable. 2Adopt fine workmanship and delicate design, smooth surface, will not scratching your guitar. 3Lightweight, easy to install and use. 4Perfect used as guitar and bass tone control knobs and volume control knobs. 5Great replacement for electric guitar and bass.