The rectangular conductive electrodes are adhesive and reusable, 'till they maintain a good adherence to the skin. For a better preservation, after every use they must be replaced on their support, trying to eliminate all the air bubbles. Once the electrodes have lost their adhesiveness, they must be replaced with original refills. The following dimensions are available: 3.5 x 4.5 cm , 4.5 x 5 cm and 5.3 x 9.6 cm.