The optional Caldera Blank collar is a kiln section that stacks onto the Caldera or Caldera-S kiln. The Caldera collar adds 4 ½" of height to the kiln. The collar has no heating elements. The Caldera and Caldera-S, even with a collar, still fire to 2000°F/1093°C. The Collar is made of 2 ½" insulating refractory firebricks.
