The Alliant Power AP0029 Fuel Filter Base & Hand Seal Kit is designed to rebuild the fuel filter base (also known as a fuel filter head) found on your 2001-2010 GM 6.6L Duramax. this kit includes new seals along with a brass screw to allow a complete re-seal of the factory fuel filter base, rather than replacing the entire unit when worn or cracked seals create air leaks of the other priming issues in your fuel system.