Murata’s piezoelectric sound components are offered in a variety of materials and styles. Most are supplied with brass diaphragms, nickel, and stainless steel. Brass types can be provided with lead wires attached in the 12, 27, 35 and 41mm diameter sizes for either the 2-electrode (external drive) or 3-electrode (self-drive) styles. Sizes and resonant frequencies range from 12mm (9.0 kHz) to 41mm (2.2 kHz). These products require a resonant enclosure (by others) for proper operation. All are RoHS compliant.