OPGUD PR2 is an ultrasonic pulser suitable for work with all ultrasonic transducers with about 500pF - 20nF impedance.
http://www.optel.pl/manual/image/opgudpr22d.jpg

Method of operation:

The rising edge of the Trigger signal (see picture) initiates the transducer charging process. After this time, the falling edge of the Trig_Out is generated which indicates the end of the transducer charging process and a transistor switch which discharges the transducer is turned on. ·

Pulse amplitude: 100V - 1300V
Duty: 50% - 95%·
Frequency: 0.7 - 170Hz
Trigger output/input: TTL