ISO-TOP CONSTRUCTION SHEETS WF3 are made from Thermopore, a high-strength EPS-based construction material. We have been using this material for many years for in front of wall installation with our ISO-TOP WINFRAMER TYPE 3 system. You can even have the ISO-TOP CONSTRUCTION SHEETS WF3 custom manufactured to size: - windowsill connection profiles - supporting profiles - packing strips - for floor-level windows - for adapting roller shutter casings and venetian blind boxes - other shaped parts