The Model 77068 Heart Rate Monitor when used in conjunction with any electronic multiple function amplifier is designed to be used as an independent monitoring device that produces a permanent recording of increases and decreases in the subject heart rate. An LED light flashes synchronously with each beat of the heart. A 5 beat-per-minute calibration push button is provided and also serves as a battery test button during operation. A mode selector is available for recording either beat-to-beat or average heart rate. A 9V battery is included.