Lively flames with a large ember bed are features of the G18 Propane Vent Free Burner System - 16"/18". This burner will add efficient heat and unmatched beauty to your fireplace. This burner features seperate flames for added realism. Available with variable remote for this propane system. This vent free gas log set operates on propane with the chimney flue closed, and is an efficient heat source because 100% of the heat generated stays in your home. Vent-free burners add moisture to the air, so it's important to install them in a room with proper ventilation to avoid formation of mildew. Please Note: Before installing any gas burner system, check your local and state codes. Minimum Firebox Dimensions Front Width 22" x Rear Width 20" x Depth 13" x Height 18" - 24"