aFe Power's new rear differential cover brings performance engineering to the protection of your axle's differential. This differential cover is constructed out of durable A356-T6 cast aluminum with reinforcing ribs for maximum strength. Mounting hardware is included for a hassle-free installation. An oil level sight glass and calibration plug set to the factory level prevents overfilling of the differential. A magnetic drain plug and a deep reach magnetic fill plug are provided for maximum protection. This cover is finished in black powder-coating with machined fins for a distinctive look. 4 Quart Gear Oil Capacity: This cover has about a 4 quart gear oil capacity at the factory fill level, factory cover holds about 3 quarts. Built-in External fins: Built-in external fins transfer heat from the fluid to the outside air for maximum cooling. Magnetic Drain/Fill Plug: This system incorporates a magnetic drain and deep reach fill plug that captures loose particles for maximum rear-end protection. Oil Level Sight Glass: Large oil level sight glass with 1/8'' NPT calibration plug set to the factory fluid level to eliminate overfilling. Group IV synthetic base: This competition proven formulation utilizes a group IV synthetic base along with a proprietary additive package that reduces drag, resist foaming and maintains its viscosity under extreme heat and high loads. Usage: The PRO Guard D2 Synthetic 75W-90 limited slip gear oil exceeds the performance requirements of API GL-5 recommended for both open and limited slip applications. When it comes to engineering for power, performance, protection and value, aFe Power is the only choice.