The Dundee Oak 18 in. Vented NATURAL Gas Log Set has more to offer, combining luxury and quality with technology. This 18 in. gas log set uses a single burner tube and will provide up to 74,000 BTU's/hour. Made of refractory high heat cement providing years of enjoyment. Our logs are each hand painted to capture a natural look found in nature. No more ash, no more cutting wood, and no more hassle. Simply sit back, relax, and enjoy. Whether your logs are burning or not, they will provide genuine fireplace elegance inspired by nature all year long. This Gas Log Set must be operated with the flue in the open position at all times. Material: Concrete.