HY-C T2UL1848BL-1C Type 2 Hearth Extender, 18 48-Inch, Black Provides non-combustible thermal and ember protection for floors and walls from the intense heat, hot coals, ashes and soot that wood burning appliances can produce Use as a stove board or hearth extender to protect the floor in front of your fireplace or as a wall shield to protect your walls Embossed printed steel and 1/2" thick, specially formulated fiber board backing Tested to UL1618; R-Value: 1.56 Made in the USA