MC150 is an elastomeric, one component, general purpose fire rated sealant, acoustic sealant and smoke seal for construction joints and through-penetrations. It is a water based, non-sag caulking grade sealant that is easy to apply and to retrofit. It cures to an elastomeric seal that is suitable where dynamic movement is expected. In the event of a fire, Metacaulk 150 will prevent the spread of flames, smoke, hot gases and water through joint openings and through-penetrations. No dilution or mixing is required for use.