This door glass is for the clean glass system on the Alaska Stoker stoves.
Size is 4.75" x 11" wide and bolts on the inside of the outer glass at the top of the door.
Gasket is only on 3 sides - creating a air flow over the top of outside door and down between the small glass - this creates the air-wash system.
Only can install on stoves using the k-glass (2521)