DD-770RThe DD-770R* provides a large, bright, back lit display of the pulse rate. The display also indicates battery, volume, and signal strength status. The powerful digital processor in the DigiDop utilizes Digital Signal Clarity - DSC to eliminate background noise and amplify a strong clear signal. True auto-correlation calculates a fast, accurate pulse rate.Features and Advantages:Hear the Difference: Digital Sound Clarity DSC™ amplifies the signal up to 6x for exceptional diagnostic...