Our models are created with 100% polymer foam spacer bars, which give better thermal and acoustic Attributes, added longevity, energy efficiency and mould safety in comparison with its steel counterparts. R-benefit unaffected by humidity : Stops condensation : Helps prevent 97% of radiant heat transfer : Vapor barrier : Core https://spencervywrl.bloggip.com/34704839/details-fiction-and-window-retrofit-kit