A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 5925-01-096-5269
NSN 5998-01-495-0249
NSN 5925-00-903-8025
NSN 5925-01-069-5002
NSN 6610-01-640-9367
NSN 5935-01-422-7523
NSN 5950-00-930-2102
NSN 6620-01-377-0414
NSN 5965-00-153-5216
NSN 5960-01-284-9209
NSN 5999-01-139-9761
NSN 6105-01-243-2118