Verus Engineering A/C Line Cap KitReplace those lackluster plastic caps that come from the factory with a cap machined from solid aluminum and bright anodized your favorite color. The units install easily within minutes and simple hand tools. The units fit on both R134a, like found in the GT350 GT350R and R1234yf, like found in the Mustang GT. Anodized parts can potentially fade over time due to engine bay heat.