The superheater has been installed through the superheater ring and the ring insulated.  The assembly is now ready for mounting in the car.  There are numerous manufacturers of ceramic fiber insulation products. One of the better-known manufacturers is Unifrax (www.unifrax.com) who manufactures the Fiberfrax line of ceramic fiber insulations. Another manufacturer with a diverse line of products is Thermal Ceramics (www.thermalceramics.com) marketed as Kaowool Refractory Ceramic Fiber.