... 5mm; 3. Frequency:40KHzSENSOR; 4. SPL:min.110dB 12mm 40khz receive Ultrasonic Sensor1. Diameter:12mmSENSOR;2. Height:9.5mm;3. Frequency: ... in household appliances equipment, watches, toys, alarm systems, reversing radar, ultrasonic cleaning, ultrasonic atomization, marine fish exploration, the range of ultrasound equipment etc ... contact us for business inquiry at any time! 12mm 40khz Ultrasonic Sensor