The DuraVent 5GVFF tall cone flat flashing is a great addition to your round gas vent. It protects your vent pipe from other weather elements to penetrate through the roof. This can also be used on flat roofs, masonry chimney, and chase enclosures. Made of galvalume, it measures 5 inches in diameter and requires a storm collar to complete its installation. It is a UL-listed product and is covered by DuraVents limited lifetime warranty. DuraVent has been a technological leader in the venting industry, being committed to provide innovative solutions. Search the one that you need here at PlumbersStock.com.