Made from 356-T6 cast aluminum, these girdles are then CNC machined for an exact fit and also to incorporate a reinforced crossbar. The crossbar houses the load bolts that apply pressure to the bearing caps. This feature, along with the thick casting, prevent bearing cap deflection under severe loads. Which in turn greatly reduces or eliminates (in most cases) bearing cap fatigue and failure. This cover also allows easy changing of rear differential oil, with easy-to-reach drain and fill holes. TA Performance has been manufacturing their rear girdles for over 20 year and have continued to offer the most widely used and respected girdle in the industry.