Non-invasive blood glucose tester approved by the FDA in 2001, <br />The back of the GlucoWatch blood glucose meter comes into contact with human skin through a layer of gel pad. There are two electrodes in the gel. When in use, the circuit is switched on, and a microcurrent is generated through the human skin. By measuring the degree of reaction of glucose molecules with an enzyme (glucose oxidase) in the gel, the current blood glucose level can be calculated, and the measurement results are displayed on the "watch" screen. <br />This product has been discontinued.