The HBF-400 Fat Anlyzer with Scale is easy to understand. The monitor displays the calculated value of body fat percentage using the BI (Bioelectrical Impedance) Method and indicates the BMI (Body Mass Index) in four ranges. Set your personal data. Push the power switch on, select your personal ID number, and step onto the measurement platform. Your calculated body fat percentage and body mass index is displayed in an easy-to-see screen. The personal memory function stores up to four personal profiles.