The Esse 300 is a unique solution to quickly convert an inefficient open fire into an economical multi-fuel inset stove with virtually no disturbance. It can improve the efficiency of an open fire by up to 400% (from 15% to 65% efficient) and is suitable for overnight burning. No flue pipe is required as it is designed to ‘plug in’ to a standard fireplace opening with no messy and expensive alteration.