Product Type Venting For Gas Heaters Compatible with Product Type Dayton Infrared Tube Heaters Opening Height 4 in Opening Width 4 in Mounting Type Flange-Mount Vent Direction Horizontal Vent Length 5 5/8 in Vent Diameter 4 in Vent Size 4 in Vent Type Sidewall Outside Air Inlet Cap Material Galvanized Steel Outer Diameter 4 in Overall Length 5 5/8 in Includes Bird Screen Standards UL Listed