3” Flange high temp

Inner-Lining Insulation is 1” high-temperature fiberglass mat mechanically bonded to withstand temperatures up to 1200° F (1000° F continuous). Stainless-steel wire blanket mesh next to the heated surface. 
Outer-Lining is a silicone impregnated woven fiberglass cloth that is durable and resistant to oil and water. Rated 450°F
Other materials included mild steel lacing anchors, washers, wire and dome caps.