The International, Volvo, and Mack 3 1/2 Inch Non Vented Fuel Cap is a practical and reliable solution for locking your fuel tank. With its locking feature, this cap ensures the security of your fuel supply. Designed to fit most International, Volvo, and Mack fuel tanks, this non vented fuel cap has a 3 1/2 inch diameter. Sold individually, it offers convenience and ease of use. Trust this fuel cap to provide a secure and efficient solution for your vehicle's fuel needs.