The Convertible Orifice for Air Flow will work with a gas unit with a BTU rating around 78,000 (NFPA-11). With six small holes around the yellow center hole it will work to convert to propane gas. The orifice is converted propane when the holes are covered with a special washer (included). It is set to natural gas when the washer is taken out and the six holes are open.
Please Note: Must not be operated closer than 6" from an open flame.