Pipe Insulation, Insulation Material Buna-N Rubber, Installation Style Unslit, Inside Diameter 4 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 3.2, Form Tube, For Copper Tube Size 4 1/8 in, For Pipe Size 3 1/2 in, Flame Spread Index 137, Smoke Developed Index 162, Foam Cell Type Closed, Plenum Rating Plenum Rated, Flexibility Flexible