Superior 40-inch DRT2040 Millivolt Conversion KitUpgrade your fireplace with the 40 inch Superior Millivolt Conversion Kit designed for seamless integration Why is a Millivolt Conversion Kit essential for upgrading older heating systems? A Millivolt Conversion Kit is essential for upgrading older heating systems because it provides a cost effective solution to modernize and enhance efficiency. Older systems often rely on outdated thermopile technology, which can be inefficient and prone to