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 Direct Vent, Flapper Length 4 in, Flapper Width 4 in, Material Galvanized Steel, Outer Diameter 4 in, Overall Length 5 5/8 in, Includes Flapper, Standards UL Listed. This item has been restricted from sale in the following state (s): []