The TempZone™ Flex Rolls, Easy Mats and Shower Mats are designed to deliver 15 watts per square foot (maximum allowed by the National Electrical Code), with the heating element positioned 3” apart on a serpentine loop attached to a fiber mesh. The TempZone™ Cable yields between 8-12 watts per square foot, variable, based on the cable spacing. TempZone™ Custom Mats are made to order, so the spacing of the heating element throughout the mat varies according to each specific design. The TempZone™ Custom Mats can yield from 12 to 15 watts per square foot.