It is a flat bottom, allowing you to drain all of your engine oil, so no dirty oil is left in the pan. The pan holds an extra quart of oil so you will see reduced oil temperature, higher oil pressure, and better lubrication to your engine's vital components.
And it is an unshrouded oil pickup. The engine will have no restriction near the oil pickup resulting in higher oil pressure. Higher oil pressure equals better lubrication. Also included is a billet stainless steel drain plug which contains a powerful Neodymium magnet that attracts and holds ferrous metals, keeping them from damaging your engine's vital internal components.
One quart additional oil capacity
Flat bottom allows for complete oil drainage
Cast aluminum construction reduces engine noise
Fixes complete oil drainage problem associated with GM pan
Cast from high-grade aluminum alloy for optimal heat dissipation
High-power Neodymium magnet equipped, hardened stainless steel billet drain plug
2001-2010 GM 6.6L LML Duramax Diesel