Insulation Sheet Insulation Material Polyethylene Insulation Color Black Overall Length 4 ft Overall Width 36 in Thickness 1/2 in Minimum Operating Temperature -330 Degrees F Backing Type Plain Maximum Operating Temperature 210 Degrees F Facing Material Unfaced R Value 2 Form Sheet Flame Spread Index 25 Smoke Developed Index 50 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible Standards ASTM C177 Clean Room Class Not Applicable