Pipe Insulation, Insulation Material Buna-N Rubber, Installation Style Unslit, Inside Diameter 2 7/8 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 4.8, Form Tube, For Copper Tube Size Not Applicable, For Pipe Size 2 1/2 in, Flame Spread Index 135, Smoke Developed Index 160, Foam Cell Type Closed, Plenum Rating Plenum Rated, Flexibility Flexible