Check the listing for details. 20Pcs 10mm Discs Guitar Trigger Buzzer Transducer Element. Condition: New. Listed at 15.69 USD. Description* This item are brass piezoelectric discs which are essential parts for pickups of acoustic instruments. All the discs are made from selected copper, ensuring excellent conductivity and long-lasting use. It can be easily installed and suitable for many kinds of instrument like acoustic guitars, drums. Great for acoustic instrument pickups, stomp boxes, contact mics, etc. Specifications:* Drive Type: Piezo Discs* Resonant frequency(kHz): 3.0~5.0+/- 0.5 KHz* Resonant impedance (ohms): 300 max* Diameter: 10mm/ 0.39 inches* Thickness: 0.3mm/ 0.01 inches* Wire Length: 40mm/ 1.57 Inches* Material: Brass* Color: As shown Package: 20 Pcs x Piezo Discs Note: Due to the difference between different monitors the picture may not reflect the actual color of the item .