The New Duralast Fuel Cap 6838 is a black fuel tank cap designed for easy installation without the need for any drilling or modifications. It is a non-locking, vented gas cap that meets emission standards.  The GM OEM part number is 19432733.  It fit my 2008 Chevrolet Trailblazer with the 4.2L engine.  You should check compatibility for your specific vehicle with a reputable auto parts store.