The FC-6NV from Cleveland Tank is a steel diesel fuel cap, built from a heavier, more impact-resistant material than Cleveland Tank’s aluminum or brass caps for applications where maximum toughness matters more than weight or corrosion resistance. It has a 2.88-inch diameter with a male thread design at 8 threads per inch (8 TPI), non-locking and non-vented. The male thread fits a female-threaded tank neck, the opposite of most caps in the lineup, so confirm thread gender before ordering. At 1.0 lb and 2.50 x 2.50 x 2.0 inches, the FC-6NV is a direct-fit replacement for diesel fuel systems specifying a 2.88-inch, male 8 TPI steel cap.