Bio Flame 72″ Firebox Double Sided Built-In Ethanol Fireplace - BlackDescription The Bio Flame 72" Firebox DS (48 Manual) is equipped with a powerful 33,500BTU burner which heats an average of 107m. It features a 304 stainless steel firebox construction, a double walled design, and a fully insulated brushed stainless steel internal frame. The 8mm tempered glass and 48 burner add an impressive visual touch, while the UL ULC certification ensures top safety standards. Plus, it comes with a 5 year warranty. Features