12mm 40khz receive Ultrasonic Sensor 1. Diameter:12mmSENSOR; 2. Height:9.5mm; 3. ... piezoelectric ceramic element, SMD magnetic transducers, condenser microphones, ultrasonic sensor,Atomization piece, speakers and other audio components. And our ... in household appliances equipment, watches, toys, alarm systems, reversing radar, ultrasonic cleaning, ultrasonic atomization, marine fish exploration, the ...