Rectorseal 66389 Metacaulk 150+, 5 .gal PailRectorseal 66389 Metacaulk 150+ is a general fire rated sealant for construction joints through penetrations. Prevents spread of flames smoke hot gases water. All systems rated for up to 4 hours as per ASTM E814 (UL1479) ASTM E1966 (UL 2079) test standards Features Water based and non sag. VOC compliant. Protected in wet dry stages against mold growth with a combination of biocides. Flexible set and Excellent freeze thaw. Cures to an elastomeric seal