Part Number: SMD50T30F45RPiezo Electric Ceramic Disc Transducer. Both electrodes on one side (R configuration). Radial mode vibration applicationPiezo Material: SM111Dimensions: 50mm diameter x 3mm thicknessResonant frequency fr: 44 KHz±3 KHz Electromechanical coupling coefficient Kp:≥60%Resonant impedance Zm: ≤8 ΩStatic capacitance Cs: 7200pF±15%@1kHzTest Condition: 23±3 °C 40~70% R.H.fr, Zm, Kp => Radial mode vibration applicationCs => LCR meter at 1KHz 1VrmsApplications: Ultrasonic Sensor, Vibration Sensor, Wall thickness sensor, Material stress sensor, Pressure sensor, Vibration generation, Energy/Electricity harvesting, Biodiesel mixing transducer, Fish finder transducer and others.Notes: The max voltage that this transducer can withstand is 1050V, but the most important issue is the maximum power allowed which is 55W. If input voltage is increased up to the maximum value, the power should always be kept below the max power. Of course the maximum power will be dependent on the bonding job. So the operation voltage we suggest is 280V. The wrap around electrode has the negative polarity.