12mm 40khz receive Ultrasonic Sensor 1. Diameter:12mmSENSOR; 2. Height:9.5mm; 3. Frequency:40KHzSENSOR; ... (Piezo electric, electromagnetic, mechanical), piezoelectric ceramic element, SMD magnetic transducers, condenser microphones, ultrasonic sensor,Atomization piece, speakers and other audio components. And ... us for business inquiry at any time! 12mm 40khz Ultrasonic Sensor