Heatilator 3 piece traditional brick refractory (Caliber) - BRICK-42M-WB. Options - Finish: Steely Gray; Weathered Brick. Refractory panels line the firebox, protect the metal surfaces and set the look of the fire. Panels are matched to a specific fireplace model and size, so confirm your model number and firebox width before ordering. Ships as a set sized for the firebox listed; replace cracked or spalled panels promptly to protect the firebox. Special order - contact us for a quote.