Air-Bond Ultrasonic Sensor

Your request leaves me wondering, a bit... Do you already have an ultrasonic pulser-receiver (instrument) in your possession, and are only asking for the appropriate TRANSDUCER element...?

Or, do you have a particular APPLICATION in mind, and you are asking for guidance as to what kind of complete SYSTEM you might be able to purchase, which will accomplish your goal...?

Have you already inquired to some of the manufacturers, who have already designed and built thousands upon thousands of probes for a veritable plethora of needs...?

http://www.piezotechnologies.com/

http://www.olympusndt.com/en/panametrics-ndt-ultrasonic/

http://parsonicscorp.com/

The more COMPLETE data you input, the more complete answer(s) you will receive.

Best Regards ~