... light;-Low power consumption;-No EMI\RFI. Piezo Ceramic Element: Applications (Piezoceramics element; Piezo diaphragm, piezo plate)1, For sound making: ... reflector,pedometer, car alarm sensor. Brief description of piezo ceramic element & Attributive Characters:1, Electrode form/ Modulating: External drive (diode); ... types: Brass, Nickel, Stainless steel;5, Connection terminal: Solder wire or not.