Specially cut piece of 1440 Degree, 128kg x 25mm Ceramic Fibre "Hot Face Top Rings" for the top of the kiln, behind the top row of bricks.
 
This piece provides the seal against the lid for superior insulation and heat retention.
It also supports the top layer of bricks.
 
Select your kiln and number for the kiln.
 
Mini = 6
Hexagon = 6
Octagon 3.2 & 5 = 8
Decagon =10