Available for: 2008 - 2010 CAT C15 Acert Engines Typical manufacturer’s oil fill caps that are made from plastic are know to fail and leak oil all over. Due to vibration and inferior engineering, low-quality oil fill caps have been know to come loose and fall off while driving down the road. Don’t get caught in a bind! Performance Diesel’s BIG BOSS? Oil Fill Caps are carved from solid, high-grade billet aluminum for longevity and superior performance over typical stock oil fill caps. Our Oil Fill Caps are structurally superior with a lock-tight design which has been field tested for strength and security. Keep your engine clean and running smooth.