Grafco® Advanced Mini-Doppler 4070 amplifier provides clear and distinct doppler sounds. Monitor frequency changes aurally through the speaker, visually with waveform. Records to a conventional recorder. Includes carrying case, ECG connector cable and 9V battery. 5 MHz and 8 MHz probes have 5 mm tip and interchangeable. Use of Blood Pressure Cuff (#95-600 or #95-186) is recommended.