Cast iron jet burners, fueled by propane gas are typically only used in outdoor brewing as per most municipal codes. Jet burners can not be used in closed firebox and require substantial air intake to function properly. If allowed to be used indoors, a vent hood is usually required. Orifice sizes are #63 for propane and burners come with 44, or 88 tips, with each tip producing approximately 10,000 BTUs. 
 
44 tip model: 440,000 BTU - 335USD
88 tip model: 880,000 BTU - 647USD