Insulation Sheet Insulation Material Melamine Insulation Color White Overall Length 4 ft Overall Width 24 in Thickness 1 in Minimum Operating Temperature -40 Degrees F Backing Type Plain Maximum Operating Temperature 350 Degrees F Facing Material PVC Jacket R Value 3.85 Form Sheet Flame Spread Index 25 Smoke Developed Index 50 Foam Cell Type Open Plenum Rating Plenum Rated Flexibility Flexible Standards ASTM E84 Clean Room Class Fed. Std. 100 Density 0.19 lb/cu ft