Genuine OEM Mazda Fuel Filler Neck, part number BCJH42420N. This component connects the exterior fuel filler door to the vehicle's fuel tank, facilitating the safe and efficient refueling process. It is designed to prevent fuel vapor escape and ensure proper fuel flow. Constructed from durable, fuel-resistant materials to resist corrosion and degradation. Genuine OEM fuel filler necks are manufactured to exact specifications for a precise fit and reliable connection to the fuel system.