[High Performance] - Resonant frequency of 3.0~5.0+/- 0.5 KHz, resonant impedance of 300 ohms max, low power consumption, and high sensitivity. [Compact Size] - Piezo pickup plate diameter: 27mm/1.6 inches, thickness: 0.3mm/0.01 inches; small, thin, and lightweight. Package includes 5 Pcs of buzzer films. [Durable Construction] - Made of brass and ceramic for temperature resistance, stability, durability, and a long service life. [Easy Installation] - Pre-wired piezo pickups that are easy to install, suitable for foot stompers and other DIY instruments for sound and vibration detection. [Versatile Usage] - Perfect for beginners for touch-sensors, electronic drum triggers, buzzers, creating contact mics, and various applications such as watches, cameras, phones, electronics, and computers.