The new BioWeigh-IR 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 (Bioimpedance 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. Gender: unisex.