Metacaulk® MC 150+ is a one component, general purpose fire-rated sealant and smoke seal for construction joints and through-penetrations. It prevents the spread of flames, smoke, and gas through penetration openings. Metacaulk® MC 150+ is a water based, non-sag caulking grade sealant that is easy to apply as well as to retrofit. Metacaulk® MC 150+ can be used on various penetrations such as top of the wall construction joints, deflection track wall systems, EMT, telephone and power cables in concrete floors and walls, gypsum walls as well as wood floors. Metacaulk® MC 150+ may be applied with a caulking gun or trowel. For large applications, it may be pumped from the pail. Metacaulk® MC 150+ cures to an elastomeric seal that is suitable where dynamic movement is expected. STC rating 51*. *Tested in a UL 411 wall assembly/section to ASTM E90.