<p>Designed for professional use. Must be purchased alongside the B (POLYOL) Side and the Gun Hose Assembly. When these three parts are combined, it results in a two-component, chemically cured polyurethane foam that is a Class A fire-rated insulation. It expands quickly to fill cavities, penetrations and gaps greater than two inches. Helps improve the comfort, health, safety, performance and energy efficiency of any building.</p>