Keys Fitness HT640U owner manual Console Overview, The console requires 2 AA batteries

Console Overview

HEART RATE PROGRAMS: There are 5 programs for selection. You can choose a program by using the PROGRAM button to scroll thru programs 2-5. See profile charts below for each program. This symbol will appear in the display along with the percentage of maximum HEART RATE. You must keep contact with the pulse rate grips when using these programs. You can select which percentage of your maximum heart rate that you would like to exercise at. You must also enter your AGE when using the HEART RATE programs.

The console requires 2 AA batteries.

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