Digital display body fat monitor, OMRON HBF-302. Batteries are not included. Basic type body fat monitor. Check your body fat for a healthy life from within. Since you measure with your hands, you can easily measure anytime, anywhere, without taking off your clothes or shoes. OMRON's body fat monitor measures body fat percentage by passing a weak electrical current through the body and measuring the electrical resistance value. The current flowing through the body during measurement is very weak, so it is safe for the human body and you will not feel any stimulation.