Certified as having 68.99% efficiency for natural gas and 69.12% for LP gas, the Lakefield XL offers impressive performance. Rated at 40,00 BTU/hr input for natural gas and 39,000 BTU/hr LP gas, this is a free standing gas fireplace that benefits from both excellent performance and eye-catching good looks. Fronted by traditional glass, this gas stove includes a limited lifetime warranty and offers exceptional value. "Available with natural gas or propane."