Ultrasonic Receivers and Transmitters are designed to detect and transmit high frequency sound waves, respectively. They are characterized by frequency, rated voltage, and beam angle. Their typical operating frequency range are 50Hz, 10kHz to 65kHz, 20kHz, 25kHz, 28kHz, 38kHz to 42kHz, 40kHz, 42kHz, 49.5kHz, 58kHz, 60kHz, 300kHz, 1MHz, 2.45mHz, and 168MHz.