it is made of extruded polystyrene,both sides with a fibreglass mesh embedded into a thin cement polymer mortar.it is ideal for two primary purposes; as a superior waterproof surface to fix wall or floor tiles and as a first class heat insulation for underfloor heating systems. Insulation Tile Backer boardare particularly suited to underfloor and under tile heating applications. Installation below underfloor heating systems on an existing un-insulated concrete or timber sub-floor will greatly reduce heat up time and running costs FEATURE:The boards are waterproof and dimensionally stable,low weight,one board(1200*600*10mm)is around 1.8KG,easy to cut(by knife),excellent for wet rooms,excellent sound insulation,color of the XPS foam board can be blue,pink, light yello,Normal size: (Length: 1200mm / Width: 600mm / Thickness: 10mm,we also can produce based on your requiremens or samples,MOQ:40'GP,Accessaries:fiberglass reinforcement tape,washers,screws can be provided as well.