A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 7035-01-311-5098
NSN 6650-01-152-9425
NSN 5905-01-234-1309
NSN 5925-00-369-7747
NSN 6145-00-702-0057
NSN 6105-01-545-5889
NSN 5905-01-634-0595
NSN 5945-01-293-8330
NSN 6650-01-495-1269
NSN 5998-01-094-4087
NSN 5960-01-266-1011
NSN 6320-01-106-4414