The Slendertone Replacement Pads are suitable for every Slendertone ab belt. This includes Flex, Flex Max, System Abs and System Plus. The hydrogel electrodes, used in each of the pads, comprise a three layer conductive medium to deliver the electrical current. These pads, also referred to as electrodes, have undergone rigorous safety and biocompatibility testing prior to entry into the market. The double adhesive electrodes provide an excellent means to disperse the current over a suitable area thus preventing current build up and skin irritation. This is essential to ensure the user can increase intensities to maximum levels to attain the greatest possible training effect while maintaining their comfort. The hydrogel electrodes are CE Mark approved as a Class I Device in Europe, in line with Medical Device Directive 93/42/EC as amended by 2007/47/EC.