Dead soft aluminum foil / 3-way fiberglass scrim / paper carrier coated with aggressive adhesive carried on a 3.2 mil removable paper release liner. Malleable foil conforms well to irregular and curved surfaces to maximize adhesive contact and provide quick, positive grab to the insulation surface. Used as a closure system for fiberglass and mineral wool insulation systems that are faced with foil, to seal seams and joints on aluminum faced fiberglass duct board, and to provide a vapor barrier that assures the integrity of thesystem. 3" neutral core.

Alternative to 3M #431; Compac #; Nashua # 338FSK -

Mill:

• A "mil" is a unit of thickness equal to one thousandth of an inch. 
• To convert mil to inches take mil & divide by 1000. 
• Thus, a 2 mil bag would be .002 inches thick.
• Example: Ex: 2 mil/1000 =.002 inches