Features: Quality: This dome knobs cap material is made of quality metal, bronze-coloured, strong and anti-agings, anti-rust and durable. Appearance: Classical brass knobs appearance, with non-slip texture, and you can easily use the adjuster when you are playing. Installation: Our product comes with an Allen Keys Screws Set, which is easy to install and disassemble, and is interchangeable. Protection: Our detachable knobs provide full protection for your audios converter, keep it tidy, and therefore extend its service life. About Size: Approx. 2.0x2.0x1.9cm/0.78x0.78x0.74inches, each set contains 4 pieces effect pedal caps, and 1 piece wrench. Specifications: Material: Metal Color: As The Picture Shows Package Weight: approx.50g Size: approx.2.0x2.0x1.9cm/0.78x0.78x0.74in Inner Hole Diameter: approx.6mm/0.24in (More Size Detail, Please See Photo.) Package Includes: 4Pcs Guitar Volume Tone Control Knobs 1Pc Hex Wrench note: Please allow 1-3mm error due to manual measurement. Please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks!