This cover has an increased oil capacity over stock for better performance over a longer duration. Built-in internal and external fins transfer heat from the oil to the outside air for maximum cooling. This cover incorporates a magnetic drain plug to capture loose particles for maximum protection. A calibration plug is set to the factory oil level to prevent overfilling. Our optional deep reach magnetic fill plug (PN: 46-00002) is a great addition to combine with this cover. This item fits vehicles equipped with AAM 11.5/12.0 Rear axles.