Combustion Air Intake System For Fuel Type Oil Maximum Appliance BtuH Input 490 000 BtuH Maximum Airflow 325 cfm Nameplate Voltage 120V AC Compatible System 120V Appliance Inlet Diameter 4 in Outlet Diameter 4 in Oil Appliance BtuH Input Max of 3.25 GPH Minimum Vent Pipe Diameter 4 in Maximum Vent Pipe Diameter 6 in Overall Height 12 1/2 in Overall Length 10 1/4 in Overall Width 9 1/4 in Standards ETL Listed Current 0.8 A