Banks Ram-Air differential cover extends lubrication life and retains fuel economy. Thanks to its superior fluid and aerodynamics, the Ram-Air Cover out-performs stock and flat-back high-capacity covers and does so with less lubricant. Increased distance between service intervals and less lubricant means you'll save money while extending gear life. When it comes to product development, we only make products that increase performance and beat the competition. So when we tested the popular Diff Covers on the market, we were shocked to find out that they actually hurt performance. This lead to the development of something so New and Incredible that our performance design has a United States Patent. Look, when we set out to build a product for your vehicle, we only engineer the best. What else would you expect from a company with a winning legacy that spans decades. We are here to win, and we just did (AGAIN) in a huge way US Patent # 10,443,705 B1