The ODS Pilot is designed to monitor the combustion air for the pilot. The flame will diminish if there is a reduction of air in the vicinity of the pilot and cause the appliance to shut off. Required for all vent free gas appliances under the national codes and cannot be converted from one gas to another. It is a safety device and the appliance should not be operated if it is not functional. Some thermocouple's maybe field changed while others may require a change of the complete pilot assembly.