Pipe Insulation Insulation Material Buna-N Rubber Installation Style Unslit Inside Diameter 1 5/8 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 5.2 Form Tube For Copper Tube Size 1 5/8 in For Pipe Size 1 1/4 in Flame Spread Index 131 Smoke Developed Index 156 Foam Cell Type Closed Plenum Rating Plenum Rated Flexibility Flexible