The Salter ultra slim analyser scale uses BIA (Bio Impedance Analysis) technology which passes a tiny electrical impulse through the body to determine fat from lean tissue, the electrical impulse cannot be felt and is perfectly safe. Contact with the body is made via stainless steel plates on the platform of the scale. This method calculates your personal weight, body fat, total body water and BMI giving you a more accurate reading of your overall health and fitness. It can even store personal data of up to 8 users. With an easy to read display and removeable feet for more accurate reading on carpets.