Easily and efficiently replace your old, worn, or leaking o-rings instead of the entire fuel line assembly. It is also advisable to replace the o-ring each time you remove the fuel fitting to prevent leaks upon re-installation. Part Number 800-013 (Alternate P/N: 217-452, 22514722, 22516256). This set includes o-rings for 5/16” and 3/8” fuel lines, with 7 o-rings of each size, making a total of 14 o-rings. The 5/16” line o-rings have dimensions of 1/4” ID x 3/8” OD, while the 3/8” line o-rings measure 5/16” ID x 7/16” OD. They are molded from high-temperature, low compression set FKM/Fluorocarbon rubber (also known as Viton) for enhanced performance and durability.