Petrol tank coverworks by closing gas tank filler hermetically and prevents water, dust, and other contaminating particles from entering the tank. This product is made from sturdy and high quality alloy to hold the gas tank tightly. Besides, it is chemical resistant and lightweight. Each petrol tank cover is anodized with nice finishes. It also features an easy locking mechanism. The tank cap provides sufficient pressure relief to prevent tank rupture and adequate vacuum relief to facilitate gas flow from the tank.