With an efficiency of 773 when burning seasoned wood this stove over time will not be harmful to the environment and will save you money on your heating bills the carron 11kw double door multifuel defra approved stove is timeless and will create a warm and cosy glow to your fireplaceprimary amp secondary air control for cleaner glassmultifuel grate amp external riddle grate mechanism with removable handlecleanburn airwash systemdefra approvedtop or rear flue options4 piece fire clay