Ultrasonic transducers as used in Silicon Chip projects such as the ultrasonic cleaner and boat antifouling. See website for data sheets.
35W 42kHz Ultrasonic Transducer Cat AU-5554
Specifications:
• Static capacitance: 2500pF
• Resonant frequency: 42kHz
• Bandwidth: 3.9kHz
• Impedance: 25 ohms
• Insulated impedance: 1000Mohms
• Power: 35W