Earth's Flame-A Hybrid Clean Burn System is made of 304 Stainless Steel. Eatth's Flame, a wood burning system, replaces your wood burning grate. During the burn the gas is left on to help create good combustion beneath the Ceramic Refractory. The debris from the wood logs will hit the grooves in the refractory and fall back down for a reburn. A hot coal bed is created and the heat in the room is increaed up to 115%. While burning wood and running the gas, (at a cost of around .31 per hr) carbon monxide is greatly reduced in the room, up to 60%. The frireplace draft is increased by up to 76% and emissions in the air are reducted by up to 78%, below the EPA 2012 standards.Earth's Flame is qualified by the EPA and is listed on their Clean Burn web site.