Pipe Insulation Insulation Material Buna-N Rubber/PVC Installation Style Unslit Inside Diameter 4 1/2 in Wall Thickness 1 in Overall Length 6 ft Minimum Operating Temperature -297 Degrees F Maximum Operating Temperature 220 Degrees F Facing Material Unfaced Color Black R Value 5.6 Form Tube For Copper Tube Size Not Applicable For Pipe Size 4 in Flame Spread Index 62 Smoke Developed Index 87 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible