The PPE 138051000 Heavy Duty Differential Cover for your 2001-2015 GM Duramax & 2003-2015 Dodge Cummins is cast from A356-T6 aluminum alloy. The Cast aluminum finish and greater surface area optimize heat transfer for cooling. Prolongs life of rear differential gears by reducing oil temperature. Robust side ribs provide additional strength. Includes 3/8??? NPT stainless steel drain plug and 1??? sight level / fill plug with a powerful Neodymium magnet to attract & hold harmful ferrous metals. Easy installation with included fasteners. High quality CMP - 4000 high performance gasket.