Pipe Insulation Insulation Material Buna-N Rubber/PVC Installation Style Unslit Inside Diameter 2 7/8 in Wall Thickness 1/2 in Overall Length 6 ft Minimum Operating Temperature -297 Degrees F Maximum Operating Temperature 220 Degrees F Facing Material Unfaced Color Black R Value 2.8 Form Tube For Copper Tube Size Not Applicable For Pipe Size 2 1/2 in Flame Spread Index 30 Smoke Developed Index 55 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible