Gas vents allow the flow of air to and from the tank as levels and temperature changes. The importance of gas vents such as  quality is important to prevent blow-back when filling up the tank, and vacuum build-up when gas leaves the tank. Having a very flush design, this 90° gas fuel vent has a 1-1/2" hole size, max hull thickness of 7/16" and a hose size of 9/16″. Including the screen and 2 cups, this highly polished vent is investment cast 316 stainless steel—being extremely durable for long-term use without corrosion.