The Vivitar PSV527C Body Analysis Digital Bathroom Scale is the perfect partner in helping you achieve your weight maintenance goals. Body Fat percentage, Total Body Water, Muscle Mass percentage, Bone Mass and Calories are calculated using Bio-Electrical impedance Analysis. The technology allows you to easily calculate your body fitness by imputing information of gender, height, age, activity level and your weight. With bare feet, this technology sends a low-level electrical signal through your body fat and then measures the resistance the signal encounters. This signal is perfectly safe and will not be felt. This scale is also programmable to be set to either the traditional English or Metric System of Unit Measurement. Operates on 1 CR2032 Lithium Battery included.