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