Internal Ceramic Beads - Tumbles gas to create a dancing flame every time See-Through Burner - Accommodates double sided log sets for your see-through fireplace Millivolt Valve - Includes an on/off switch For Use with - Empire "LSU" log sets of the same size Burner Size - 30-Inch; Fuel Type - Propane The White Mountain Hearth VFSUR30P Ventless Double Sided Slope Glaze Burner with Millivolt Valve, 30-Inches, Propane raises the standard for flame presence while integrated ceramic beads tumble the gas to form an ultra-realistic fire. The See-Through Vent-Free Slope Glaze Burner can reach up to 40,000 BTU while the Millivolt Safety Valve includes an on/off switch to allow easy control over your flame presence. This burner requires an Empire LSU log set in a matching size for optimal Double Sided or Peninsula fireplace performance. Empire's focus on high quality construction and performance ensures a burner system that you will be able to enjoy for years to come.