Superior FGCK-D35MNP Natural Gas to LP Conversion Kit. This Kit is designed for the multi-view see-through SSDVST gas-burning, direct-vent fireplace. Superior fireplaces and log sets from Lennox Hearth Products are all part of their extensive variety of styles and configurations, only available to trade professionals. The Superior FGCK-D35MNP Natural Gas to LP Conversion Kit is the only way to convert the above system. LP is great alternative to natural gas within the home.