These are refractory fiber module block utilizing an accordian pleat. The block contains stainless steel hardware that mounts onto a welded stud. All metallic hardware is protected from the heat. These blocks are identical  to the Z-Blok. Maximum continuous temperature is 2300 F. The block is compressed and retained to allow installion on the wall. The straps are cut after installed and the block expands filling the void. These require the use of 5/16"" studs that are sold separate.

The block comes in a box containg six modules although modules can be bought separately.