Avenger Dual Fuel Vent Free Infrared Heater - 30,000 BTU, Model# FDT3IR 1 Unit operates off Natural Gas or Liquid Propane. 30,000 Maximum BTU When Using Natural Gas \ 28,000 Maximum BTU When Using Propane Gas Thermostat Control  The control automatically cycles the burner on and off to maintain a desired room temperature. Newly redesigned cabinet for slimmer profile! Economical: 99.9% efficient. No outside duct or chimney needed! Heats Up To 1,400 Sq. Ft. Patented DUAL FUEL TECHNOLOGY. Safety Assurance: O.D.S. (Oxygen Depletion Sensor) included with automatic shut-off. PFS Certified Product Dimensions: 25.7" H x 25.5" W x 9.84" D. \Product Weight: 29.8 lbs. \ Ship Weight: 35.1 lbs. \ This Item Is Not for Sale To Residents In California. \ Vent-Free heaters do not operate at elevations above 4,500 feet altitude.