PRO Guard D2 Synthetic 75W-90 Gear Oil: The supplied gear oil (4 quarts) exceeds the performance requirements of API GL-5 recommended for both open and limited slip applications. Increased Oil Capacity: This cover has an increased oil capacity over stock for better performance over a longer duration. Built-in External Fins: Built-in external fins transfer heat from the oil to the outside air for maximum cooling. Magnetic Plugs: This cover incorporates a magnetic drain and deep reach fill plug to capture loose particles for maximum protection. Calibration Plug: A calibration plug is set to the factory oil level to prevent overfilling. Oil Level Sight Glass: An oil level sight glass allows quick and easy oil inspection. Fitment Note: This item fits vehicles equipped with Dana 60 front axles. Emissions Disclaimer: This product does not require a CARB EO#. When it comes to engineering for power, performance, protection and value, aFe POWER is the only choice.