Pipe Insulation, Insulation Material Cellular Glass, Installation Style Slit in Half, Inside Diameter 4 1/2 in, Wall Thickness 1 in, Overall Length 2 ft, Minimum Operating Temperature -450 Degrees F, Maximum Operating Temperature 900 Degrees F, Facing Material Unfaced, Color Black, R Value 3.45, Form Tube, For Copper Tube Size 4 1/2 in, For Pipe Size 4 in, Flame Spread Index 25, Foam Cell Type Closed, Plenum Rating Plenum Rated, Flexibility Rigid, For Tube Outside Diameter 4 1/2 in