Pipe Insulation Insulation Material Buna-N Rubber Installation Style Unslit Inside Diameter 4 1/2 in Wall Thickness 3/4 in Overall Length 6 ft Minimum Operating Temperature -297 Degrees F Maximum Operating Temperature 250 Degrees F Facing Material Unfaced Color Green R Value 4.6 Form Tube For Copper Tube Size Not Applicable For Pipe Size 4 in Flame Spread Index 138 Smoke Developed Index 163 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible