Features: 100% Brand New and High Quality Uncased piezo elements Speech and music applications Wide tonal response 12mm with flying leads Specification: Resonant frequency(KHz) Fs=9.0¡À1.0 Resonant impedance(¦¸£ Rr¡Ü500¦¸ Capacitance at 120Hz(NF) Co=11¡À30% Operating Temperature(¡棩 -20¡×+70 Storage Temperature(¡棩 -30¡×+80 Color: As the pictures shown Material: Copper,PVC Size: Metal Plate Diameter(mm) : 12 Cable Length: 7cm Quantity: 20pcs Net Weight: 5g Note: Lighting, display and other factors may cause COLOR SHADING, please comprehensive pictures and text descriptions to determine! Package Includes 20 x 12mm Buzzer Sensors