String Instrument Accessories -Pre-wired Piezo Pickup Generic Highlights Pre-wired Piezo Pickup Small and exquisite, give you the best sound. No soldering required, just drill two holes for the jack and glue on the piezo Easy to install, convenient to use. Great replacement for other mics and will surprise you. Suitable for guitar, violin, mandolin, banjor, etc. Material: Copper and Plastic Specification: A VOLUME: B500K Size Chart: Piezo Diameter: Approx. 29 mm / 1.14 inch Package includes: 1 piece Piezo Pickup 1 piece Volume Knob 3 piece Mounting Hardware Note: Due to the difference between different monitors, the picture may not reflect the actual color of the article. Due to manual measurement, there may be 1-2mm error in size.