Ultrasonic ceramic cartridges, of high quality, can be used as US microphone (receiver UST-40R) or as signal transmitter (transmitter UST-40T), e.g. for alarm systems. Sensitivity | - | Frequency | 40 kHz, ±1 kHz | Sensitivity | 5.0 mV/Pa/1 kHz | Capacitance | 2,400 pF | Input signal | - | Dimensions | Ø 16 mm x 12 mm | |