Newman Medical DD-330 Vascular DopplerDD 330 Non display Digital Vascular Doppler These audio only Dopplers provide great value if all you need is to hear the Doppler sounds loud and clear. They include a display of battery condition, signal strength, and volume setting, but do not have a heart rate display. Superior sound quality Our Dopplers have the sensitivity and audio response to allow you to hear the blood flow sounds quickly and clearly. All DigiDop Dopplers have our state of the