Levelling course
Serves to level out different heights and unevennesses between the foundation and the first normal brick layer of the furnace wall.

Labyrinth plate
It provides an offset (labyrinth) between the upper and lower parts of the kiln wall, thereby providing an indirect seal between the kiln car level and the upper wall segment.

Standard brick (NF)
Base brick of the kiln wall.

Peep hole brick (FE2)
Peep hole bricks provide a view into the tunnel kiln.

Anchor bricks (FE6/FE7)
Connecting elements between kiln wall and outer steel structure.

Expansion joint bricks (FE4/FE5)
Compensation of the wall section movements caused by heating up/cooling down. They also serve to secure the anchor bricks in the kiln wall.