The E33 large gas fireplace insert is a high-efficiency heat source that is designed to seal old drafty fireplaces and provide controllable gas heat. With a standard variable-speed blower, the E33 helps circulate air within the room, distributing it further than radiant heat alone. As part of our full line of direct vent gas fireplaces, the E33 is a sealed system that uses outside air for combustion – making it perfect for airtight homes.