The 864 CF 31K GS2 is perfect for medium sized rooms or as a beautiful, decorative fire all year long. It features a wide Mj turn down range for more heat flexibility and flame viewing options. The 864CF 31K G2S features 864 square inches of viewing area. You have virtually unlimited flame variation with the Comfort Control switch and the variable flame control. Use all 31Mjs of flame on the coldest winter nights or turn it down to only 7Mj (NG) or 5.5Mj (LPG) for a romantic firelight on a warmer night.