Ultrasonic transducers as used in Silicon Chip projects such as the ultrasonic cleaner and boat antifouling. See website for data sheets.
50W 40kHz Ultrasonic Transducer Cat AU-5556
Specifications:
• Static capacitance: 3000pF
• Resonant frequency: 40kHz
• Bandwidth: 3.9kHz
• Impedance: 15 ohms
• Insulated impedance: 1000Mohms
• Power: 50W