ProCom 29 inch Universal Propane Natural Gas Vent Free Firebox Model# FBNSD28T 26,000 Maximum BTU using natural gas or liquid propane Heats up to 1,350 sq. ft. Thermostat controlled to maintain desired temperature Oxygen Depletion Sensor included with automatic shut-off for your safety Dimensions: 29.1"W x 13.9"D x 23.9"H