More than a pedometer which only measures steps taken, this accelerometer calculates calories burned from physical movements, including those that do not require walking, such as gardening, housekeeping, or office work. Similar to technology used by NASA to monitor the movements of astronauts in space, the device only requires you to enter your weight and it uses a precision motion sensor to measure the frequency, duration, and intensity of your movements, and converts this information into calories burned. About the size of a pocket watch, the accelerometer clips to a belt and the hinged face allows you to read the LCD without removing it from your waist. A nine-day memory feature allows you to track your progress. Includes one CR2032 button-cell battery. 2 1/2" sq. x 1 1/4" H. (1/2 oz.)