This glass fronted convector fire has a 78% net efficiency and incorporates the classical elegance of cast iron and side windows so flames can be seen from all angles. Safety: Flame Supervision Device (FSD) Type of Heat: Radiant & Convected Heat Input High: 6.0 kW Heat Input Low: 1.8 kW Heat Output High: 4.3 kW Heat Output Low: 1.0 kW Air Vent required: Not normally Builders Opening Sizes: Height: (min) 525 mm (max) 650 mm Width: (min) 305 mm (max) 440 mm