Pipe Insulation Insulation Material Melamine Installation Style Hinged Inside Diameter 3 1/8 in Wall Thickness 1 in Overall Length 4 ft Minimum Operating Temperature -40 Degrees F Maximum Operating Temperature 350 Degrees F Facing Material Unfaced Color Gray R Value 4.86 Form Tube For Copper Tube Size 3 1/8 in For Pipe Size Not Applicable Flame Spread Index 25 Smoke Developed Index 50 Foam Cell Type Open Plenum Rating Plenum Rated Flexibility Flexible