A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 5945-01-406-2330
NSN 6685-01-219-9754
NSN 6130-01-270-5096
NSN 6650-00-330-0108
NSN 4140-00-224-2133
NSN 5910-00-128-0840
NSN 5998-00-081-1454
NSN 6620-01-561-7923
NSN 5930-01-583-2179
NSN 6220-01-329-3446
NSN 7035-01-240-0541
NSN 5835-01-595-1131