Insulation Sheet Insulation Material Buna-N Rubber/PVC Insulation Color Black Overall Length 4 ft Overall Width 36 in Thickness 3/4 in Minimum Operating Temperature -40 Degrees F Backing Type Plain Maximum Operating Temperature 220 Degrees F Facing Material Unfaced R Value 3 Form Sheet Flame Spread Index 25 Smoke Developed Index 50 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible