Pipe Insulation Insulation Material Buna-N Rubber/PVC Installation Style Slit with Adhesive and Flap Inside Diameter 4 1/8 in Wall Thickness 1/2 in Overall Length 6 ft Minimum Operating Temperature -70 Degrees F Maximum Operating Temperature 220 Degrees F Facing Material Unfaced Color Black R Value 3.1 Form Tube For Copper Tube Size 4 1/8 in For Pipe Size 3 1/2 in Flame Spread Index 107 Smoke Developed Index 132 Foam Cell Type Closed Plenum Rating Plenum Rated