The 1590WPFL is part of the Hammond line of building materials from the Home Depot. It is an expanded polystyrene (EPS) building panel that is used for a wide variety of applications, including insulation, sheathing, backing for walls, soffits, roofing, and decking. It is available in a variety of sizes, and can be cut to spec to meet any custom projects. The 1590WPFL offers superior performance over other foams, with its R-value of 5.7 per inch, making it an excellent option for energy-efficient home construction. Additionally, its closed-cell structure provides moisture resistance and improved structural integrity. This product contains no formaldehyde or other toxic chemicals, making it safe for use in homes.