16" wide. Check your furnace dimension and make sure the 16" wide plate will fit. If needed, item 26511J is narrower (15-5/8"). There is some variability on the width of the furnace chamber.
Bonded silicon carbide one piece hearth plate with curb on sides and rear.
Dimensions 31.5"(800mm) long x 16" wide(406mm)
Overall height: 2"(51mm). Curb width: 1.25"(32mm)
Floor thickness: 0.75"(19mm)