Features: Quality Material: The guitar piezo element disc is made of quality brass material, anti-aging, with long service life. Quantity Option: The discs leads piezo comes with 20mm/27mm/35mm size available, meeting your different use needs. Wide Applications: This piezo disc is very suitable for folk, acoustic guitar, and for cigar box guitar, drum triggers, and etc. ​ Simple Installation: This piezo sensor element with simple installation procedure, easy to use. Small, thin and lightweight. High Sensitivity: The drum triggers disc with high sensitivity, reliable and stable, Resonant Impedance:300Ω biggest; Static Capacitance: 50000PF +/- 30%. Specifications: Material: Brass Color: As The Picture Shows Diameter Options: 20mm/27mm/35mm Size: As The Picture Shows Package Includes: 15Pcs Piezo Disc Transducer note: Please allow 1-2cm 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!