4pcs Fit For Delphi Fit For Euro3 Fuel Injector Common Rail Control Valve 28538389 28440421. number 28538389 28440421 Fuel injector return line can improve fuel delivery efficiency for efficient engine operation. The internal seal ring helps decrease fuel contact and maintains consistent operation over time with robust construction. Made from quality materials, the nozzle provides strong resistance to aging, reliable strength, and extended durability for dependable performance.