TYVAGR5015 Tyvek Airguard Reflective is a low emissivity internal vapour barrier that combined with an airgap can enhance thermal comfort by reflecting up to 95% of radiant heat back into the building. This strong 100% airtight vapour barrier is specially designed to give maximum thermal performance. Recommended for use with Tyvek Reflex products, Airguard Reflective provides a good way to improve U-values in buildings. A highly vapour and water-resistant low emissivity internal vapour barrier, it considerably reduces interstitial condensation as well as improves thermal efficiency by reflecting up to 95% of radiant heat.