The company Exafan, S.A. manufactures plates of water of heating of 1.200 x 400 mm in concrete polymer, that facilitate a heat homogenised in all the surface. Robust and resistant, project the heat only in the surface of contact with the lechón. With and without flaps of support (of stainless steel), these plates can adapt to any type of floor and present an isolated zone with poliuretano injected, to avoid losses calóricas, and some strong stick to the concrete. Besides, the surface antideslizante of stainless steel does that it was hygienic and of easy access. They have a serpentín of tube of polyester reticulado of 16 mm of diameter and do not present internal intersections, what avoids the incrustaciones of the cal and other devices.