This Duluth Forge Ventless Zero Clearance Fireplace Insert allows you to build a custom fireplace for your home. You can pair this Duluth Forge fireplace with a face mantel or recess it directly into a wall of your home. This fireplace insert includes many features like remote control functions, Oxygen Depletion Sensor with automatic shut-off, battery assisted piezo ignition, and much more. Using Natural Gas or Liquid Propane, the Duluth Forge Vent Free Fireplace Insert radiates 26,000 BTU of heat, enough to heat 1,350 sq. ft. of space. When you buy Duluth Forge remote control gas fireplaces, you know you're getting the best quality available. Material: Iron.