Pipe Insulation Insulation Material Buna-N Rubber/PVC Installation Style Unslit Inside Diameter 1 3/8 in Wall Thickness 3/4 in Overall Length 6 ft Minimum Operating Temperature -297 Degrees F Maximum Operating Temperature 220 Degrees F Facing Material Unfaced Color Black R Value 4.9 Form Tube For Copper Tube Size 1 3/8 in For Pipe Size 1 in Flame Spread Index 76 Smoke Developed Index 101 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible