Genuine OEM Ford Reductant Tank Lock Ring, part number 5144760. This lock ring is designed to secure the cap or sensor onto the reductant tank, ensuring a proper seal for the Diesel Exhaust Fluid (DEF) system. It is crucial for maintaining the integrity and functionality of the emissions system. Manufactured to exact specifications, this genuine OEM part guarantees a precise fit and reliable performance. Using OEM parts ensures the correct sealing and operation of your vehicle's emissions control system.