1/2 in x 48 in x 48 in Calcium Silicate High Temperature Insulation, Johns Manville, Mfr#: 638330

High Temperature Insulation, Density 40 lb/cu ft, Facing Material Unfaced, Flexibility Not Applicable, Foam Cell Type Closed, Form Board, Insulation Color White, Insulation Material Calcium Silicate, Maximum Operating Temperature 1,700 Degrees F, Minimum Operating Temperature 0 Degrees F, Overall Length 4 ft, Overall Width 4 ft, R Value 0.52, Thickness 1/2 in, Standards ASTM C656, C795, E119, E136, E72, E84, NFPA251, UL 1479, UL 1709, UL 263, Water Vapor Absorption Minimal