SilverGlo is an insulation is a rigid foam board. This products is made of several layers that all have reflective coating, making this not only a physical thermal insulatorthermal insulatorThe insulating capability of a material is measured as the inverse of thermal conductivity (k). Low thermal conductivity is equivalent to high insulating capability (resistance value). In thermal engineering, other important properties of insulating materials are product density (ρ) and specific heat capacity (c).https://en.wikipedia.org › wiki › Thermal_insulationThermal insulation - Wikipedia, but also effective as radiant barrier. Radiant barrier is a reflective agent that keeps external heat out.