Features:1.Model: TCT40-16R/T (16 mm in diameter)2.Nominal frequency (KHz): 40KHz3.Emission sound pressure at10V (0dB = 0.02mPa): ≥ 117dB4.Receiver sensitivity at40KHz (0dB = V / ubar): ≥-65dB5.Electrostatic capacity at1KHz <1V (PF): 2000 ± 30%One for reception and another one for the launch, the transceiver sub body, T is thetransmitter, R is the receiver.T word launch head, the R word is receiving headTransceiver, said the sale, not split. The above price is the price of the transceiver.package include:2pcs(1 pairs) TCT40-16R/T Ultrasonic Transducer Sensor