Features 1、Suitable for folk guitar, for cigar box guitar, drum trigger, etc. 2、Simple installation procedure, easy to use. 3、6pcs, 12pcs and 18pcs are available, meeting your different use needs. 4、High sensitivity, reliable and stable, and red wire is positive pole and white wire is negative pole. 5、Made of quality material, anti-aging, long service life. Specification Features: Suitable for folk guitar, for cigar box guitar, drum trigger, etc. Simple installation procedure, easy to use. 6pcs, 12pcs and 18pcs are available, meeting your different use needs. High sensitivity, reliable and stable, and red wire is positive pole and white wire is negative pole. Made of quality material, anti-aging, long service life. Specification: Condition: 100% Brand New Material: Copper Color: Random Resonant frequency: 4.6 +/- 0.5 KHz Resonant impedance (ohms): 300 max Capacitance (nf): 20.0 +/- 30% (1 kHz) Wire Length: Approx. 23cm / 9.05in Copper Plate Diameter: Approx. 2.7cm / 1.1in Weight: Approx. 22 - 62g Packing List: 1 x Pack of 6 / 12 / 18Pcs Piezo Discs with Wires