A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 5999-01-531-6202
NSN 7035-01-441-3188
NSN 6620-00-155-2608
NSN 5920-01-073-8713
NSN 6130-01-431-4295
NSN 6145-00-185-4515
NSN 6110-01-187-4379
NSN 6105-00-005-8505
NSN 5920-01-513-1997
NSN 6130-01-218-9247
NSN 7035-00-731-8729
NSN 5935-01-617-3732