The Oracle is the equally beautiful see-thru version of the Onyx, designed to spread its warmth and light to two rooms at once. The Oracle is the only choice if you are looking for a see-thru fireplace which is clean burning and efficient. This fireplace is certified for use with 8" ICC Model EXCEL chimney. The chimney system height from the top of the fireplace must be a minimum of 12 ft. and a maximum of 28 ft. You can now create your own fireplace settings. Choose the ambiance you want and insert your choice of options with the fireplace configurator. See how RSF performance can be enhanced with the heat distribution options.