Icynene's 55 gal. Drum OC No-Mix Open-Cell Resin Spray Foam Insulation, Side B works as part of an engineered spray foam system that expands into wall cavities, gaps, penetrations, and irregular spaces to help reduce air movement and improve building envelope efficiency. When combined with the matching Side A component and installed according to manufacturer guidelines, the resulting open-cell foam creates a continuous insulation layer that supports indoor comfort and energy performance. Designed for qualified insulation professionals, this resin component is an essential part of a reliable open-cell spray foam application.