Keeping you Ready for the Road Ahead , the Fuel Tank Accessories Locking Fuel Cap defends your diesel’s fuel tank with the anti-theft fuel tank cap with a safety crossbar and chain included. To ensure this Volvo fuel cap is the right fit for your Volvo truck, always measure the fuel cap’s inside diameter. Rest confidently knowing your truck's diesel fuel remains safe with this heavy duty fuel cap. FleetPride is your First Click in Heavy Duty .