European window makers have developed uPVC window profiles that do not rely on tubular galvanised steel inserts for strength. While steel acts as an effective reinforcement, its heat-conducting properties impede energy efficiency. Belgium's Deceuninck calls its new window technology Linktrusion and is using the innovation throughout its Zendow#neo window range. In its Zendow#neo standard range, Deceuninck has replaced the steel reinforcement with a sandwich of steel-wire reinforced PVC, filled with a PVC foam in both the window frame and sash. In the Zendow#neo premium range, the PVC sandwich is used in the frame but in the sash, where strength is most important, a glass-reinforced PVC is used. Deceuninck says this reinforcement uses 200,000m of fibreglass strand per metre of window frame. Deceuninck claims the windows are "almost as strong" as their steel-reinforced counterparts but up to 30% better insulated. They also provide a 40% saving on materials and weight.