Natural Gas Unit Heater, Mbh Input:25,000, Mbh Output:20,000, Afue:80, Cfm:380, Voltage:115, Hertz:60, Phase:1, Vent Outlet Diameter:4" Round, Dims:30-1/8"H X 13-1/2"W X 27"L, Weight:72 Lbs, Reznor Series 100, Model F Gas-Fired, Gravity-Vented Unit Heaters Are Designed For 80 Thermal Efficiency And Are Designed For Use With Natural Or Propane Gas. Model F Unit Heaters Are Designed For Ceiling Suspension With A Propeller Fan For Air Delivery. This Unit Features Includes A Spark Ignition With 100 Shutoff And A Single-Stage, 24-Volt Gas Valve. A Terminal Strip Connector Facilitates Field Connection To A Remote 24-Volt Thermostat For Automatic Operation. Each Unit Is Provided With A Fan Control And All Required Limit Saftety Controls, Including An Energy Cutoff(Eco) Device And A Blocked Vent Switch. These Units Are Approved For Installation In The United States And Canada By The Canadian Standards Association(Csa), Made In Mexico, In Manufacturer Box.