North Star Health AM-190 Mark of Fitness 7-Day Pedometer and Activity Monitor uses a solid state accelerometer sensor and electronic filtering to deliver extremely accurate results. Unlike inexpensive pendulum sensor pedometers, the Mark of Fitness Activity Monitor filters out motion and vibration and only counts real steps. It measures the Intensity of activity and keeps track of how much time you spend at moderate or greater intensity level activities. The AM-190 Activity Monitor also displays your estimated basal metabolism rate and Total Calories Expenditure. Calories burned is estimated based on your personal data and the activity recorded.