Increased Oil Capacity: This cover has an increased oil capacity over stock for better performance over a longer duration. Built-in Internal/External Fins: Built-in internal and external fins transfer heat from the oil to the outside air for maximum cooling. Magnetic Plug: This system incorporates a magnetic drain plug to capture loose particles for maximum protection. Calibration Plug: Calibration plug set to the factory oil level to eliminate overfilling. Optional Accessories Available: Our optional oil level sight glass (Part Number: 46-00001) and deep reach magnetic fill plug (Part Number: 46-00002) are great additions to combine with this cover.When it comes to engineering for power, performance, protection and value, aFe Power is the only choice. Street Series Rear Differential Cover Raw w/ Machined Fins for Dodge Trucks 2500/3500 14-18 Dodge Trucks 2500/3500 14-18.