Complex sentence: In addition to the outer ceramic shell there is draft opening to provide air to the ceramic firebox in the base of the unit and there's a separate daisy wheel damper unit on the top to give air flow control and therefore temperature regulation.
Split into simpler sentences: In addition to the outer ceramic shell there is draft opening to provide air to the ceramic firebox in the base of the unit. There's a separate daisy wheel damper unit on the top to give air flow control and therefore temperature regulation.