The new quantum body composition scale from american weigh allows you view a complete breakdown of your body fat, water, muscle, and bone. the scale works on the principle of bia (bio impedance analysis). by passing a safe electrical current through your body via the metal contacts and using weight, height, and age data, your lean/fat-free body mass is calculated. this is then subtracted from your body weight to obtain body fat mass. note: although the scale uses a safe electrical current, those with pacemakers or other electronic implants should not use this scales body fat feature.