Features: Make of Metal and Wire, these piezo pickups are temperature resistant, stable. The piezo pickup plate has a diameter of 27mm, while the wire length is 30cm/11.81inch. These components are small, thin, and light weight, making it easy to install and integrate into various instruments or devices. These pre-wire piezo pickups are simple to install and can be easily used in applications such as box guitars, foot pedals, and homemade instruments that require sound or vibrations detection. With a resonant frequency of 4.6±0.5KHz and a maximums resonant impedance of 300 ohms, these piezo contact pickups offer low power consumption and high sensitivity. Specifications: Component: Metal and Wire Length: about 30cm/11.81inch Diameter: about 27mm/1.06inch Resonant frequency: 4.6 ± 0.5KHz Resonant impedance: maximums value of 300Ω Statics capacitance: 20.0 ± 30% (1KHz) Package Includes: 15Pcs Copper Sheet Buzzer note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.