JM Corbond® High Yield Open-cell (HY OC) Spray Polyurethane Foam insulation is a two-component, low-density, E84 Class A rated, nonstructural insulation system designed for interior commercial, residential and industrial applications. JM Corbond HY OC is 100% water blown. JM Corbond HY OC offers the highest yield of any JM Corbond open-cell product. Its superior performance and exceptional sprayability make it an ideal choice for high-performing energy efficient buildings.