Thermal Insulation Sheet, Insulation Material Buna-N Rubber, Insulation Color Green, Overall Length 4 ft, Overall Width 3 ft, Thickness 1 in, Minimum Operating Temperature -40 Degrees F, Backing Type Adhesive, Maximum Operating Temperature 200 Degrees F, Facing Material Unfaced, R Value 3.75, Form Sheet, Flame Spread Index 25, Smoke Developed Index 450, Foam Cell Type Closed, Plenum Rating Non-Plenum Rated, Flexibility Flexible, Standards ASTM C534, EB4013