A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 5835-00-841-2650
NSN 5975-00-386-5006
NSN 5998-01-026-0684
NSN 6650-00-021-2467
NSN 4140-01-131-3124
NSN 6650-01-112-0453
NSN 4140-01-423-1647
NSN 5960-00-669-9793
NSN 2925-00-644-0028
NSN 5975-01-138-0188
NSN 5930-01-113-2809
NSN 6150-01-539-1869