GreenGuard GG60-LG XPS Insulation Board is an ideal exterior insulation, meeting your needs for multiple applications. Its 60 psi, closed-cell extruded polystyrene (XPS) construction provides superior moisture resistance. With an R-Value of 5.0 per inch of thickness, the board increases the energy efficiency of your structures. Plus it's lightweight, easy to handle, and easy to cut with a knife. It meets ASTM C578 Type VII requirements.